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Remove translated FAQs
The English FAQ has been moved to the wiki, so the translated versions should have been removed at that point as well. The FAQ_MINGW.html should have been removed when the platform FAQs were integrated into the documentation (or earlier). applied to both 8.4 and 8.5
This commit is contained in:
Peter Eisentraut
@ -1,922 +0,0 @@
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Perguntas Frequentes (FAQ) sobre PostgreSQL
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<20>ltima atualiza<7A><61>o: Sex Nov 16 10:53:50 EST 2007
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Mantenedor atual: Bruce Momjian (bruce@momjian.us)
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Traduzido por: Euler Taveira de Oliveira (euler@timbira.com)
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A vers<72>o mais recente desse documento pode ser vista em
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http://www.postgresql.org/files/documentation/faqs/FAQ.html (EN).
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http://www.postgresql.org/files/documentation/faqs/FAQ_brazilian.html
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(pt_BR).
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Perguntas sobre plataformas espec<65>ficas s<>o respondidas em
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http://www.postgresql.org/docs/faq/.
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_________________________________________________________________
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Perguntas Gerais
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1.1) O que <20> PostgreSQL? Como ele <20> pronunciado? O que <20> Postgres?
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1.2) Quem controla o PostgreSQL?
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1.3) Qual <20> a licen<65>a do PostgreSQL?
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1.4) Quais plataformas o PostgreSQL pode ser executado?
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1.5) Onde eu posso conseguir o PostgreSQL?
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1.6) Qual <20> a <20>ltima vers<72>o?
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1.7) Onde eu posso conseguir suporte?
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1.8) Como eu posso submeter um relato de um bug?
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1.9) Como eu posso saber quais s<>o os bugs conhecidos ou
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caracter<65>sticas ausentes?
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1.10) Que documenta<74><61>o est<73> dispon<6F>vel?
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1.11) Como eu posso aprender SQL?
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1.12) Como posso submeter uma corre<72><65>o (patch) ou me juntar a equipe
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de desenvolvimento?
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1.13) Como <20> o PostgreSQL comparado a outros SGBDs?
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1.14) O PostgreSQL gerenciar<61> as mudan<61>as de hor<6F>rio devido ao hor<6F>rio
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de ver<65>o em v<>rios pa<70>ses?
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Perguntas sobre Clientes
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2.1) Quais interfaces est<73>o dispon<6F>veis para PostgreSQL?
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2.2) Quais ferramentas est<73>o dispon<6F>veis para utilizar o PostgreSQL
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com p<>ginas Web?
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2.3) O PostgreSQL tem interfaces gr<67>ficas para interagir com usu<73>rio?
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Perguntas Administrativas
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3.1) Como eu instalo o PostgreSQL em um local diferente de
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/usr/local/pgsql?
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3.2) Como eu controlo conex<65>es de outras m<>quinas?
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3.3) Como eu ajusto o servidor de banco de dados para obter uma
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performance melhor?
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3.4) Quais caracter<65>sticas de depura<72><61>o est<73>o dispon<6F>veis?
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3.5) Por que eu recebo "Sorry, too many clients" quando eu tento
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conectar?
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3.6) Qual <20> o processo de atualiza<7A><61>o do PostgreSQL?
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3.7) Que tipo de hardware eu devo usar?
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Perguntas Operacionais
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4.1) Como eu fa<66>o um SELECT somente dos primeiros registros de uma
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consulta? Um registro rand<6E>mico?
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4.2) Como eu descubro quais tabelas, <20>ndices, bancos de dados e
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usu<73>rios est<73>o definidos? Como eu vejo as consultas utilizadas pelo
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psql para mostr<74>-los?
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4.3) Como voc<6F> muda o tipo de dado de uma coluna?
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4.4) Qual <20> o tamanho m<>ximo de um registro, uma tabela e um banco de
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dados?
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4.5) Quanto espa<70>o em disco <20> necess<73>rio para armazenar dados de um
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arquivo texto?
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4.6) Por que minhas consultas est<73>o lentas? Por que elas n<>o est<73>o
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utilizando meus <20>ndices?
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4.7) Como eu vejo como o otimizador de consultas est<73> avaliando minha
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consulta?
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4.8) Como eu fa<66>o buscas com express<73>es regulares e buscas com
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express<73>es regulares sem diferenciar mau<61>sculas de min<69>sculas? Como eu
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utilizo um <20>ndice para buscas sem distinguir mai<61>sculas de min<69>sculas?
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4.9) Em uma consulta, como eu detecto se um campo <20> NULL? Como eu
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posso concatenar poss<73>veis NULLs? Como eu posso ordenar por um campo
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que <20> NULL ou n<>o?
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4.10) Qual <20> a diferen<65>a entre os v<>rios tipos de dado de caracteres?
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4.11.1) Como eu crio um campo serial/auto incremento?
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4.11.2) Como eu consigo o valor de um campo SERIAL?
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4.11.3) currval() n<>o lida com condi<64><69>o de corrida com outros
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usu<73>rios?
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4.11.4) Por que os n<>meros da minha sequ<71>ncia n<>o s<>o reutilizados
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quando uma transa<73><61>o <20> abortada? Por que h<> intervalos nos n<>meros da
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minha sequ<71>ncia/coluna SERIAL?
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4.12) O que <20> um OID? O que <20> um CTID?
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4.13) Por que eu recebo o erro "ERROR: Memory exhausted in
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AllocSetAlloc()"?
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4.14) Como eu informo qual vers<72>o do PostgreSQL eu estou utilizando?
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4.15) Como eu crio uma coluna que conter<65> por padr<64>o a hora atual?
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4.16) Como eu fa<66>o uma jun<75><6E>o externa (outer join)?
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4.17) Como eu fa<66>o consultas utilizando m<>ltiplos bancos de dados?
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4.18) Como eu retorno m<>ltiplos registros ou colunas de uma fun<75><6E>o?
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4.19) Por que eu obtenho erros "relation with OID ###### does not
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exist" ao acessar tabelas tempor<6F>rias em fun<75><6E>es PL/PgSQL?
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4.20) Quais solu<6C><75>es de replica<63><61>o est<73>o dispon<6F>veis?
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4.21) Por que os nomes de minhas tabelas e colunas n<>o s<>o
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reconhecidos em minha consulta? Por que as mai<61>sculas n<>o s<>o
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preservadas?
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_________________________________________________________________
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Perguntas Gerais
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1.1) O que <20> PostgreSQL? Como ele <20> pronunciado? O que <20> Postgres?
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PostgreSQL <20> pronunciado Post-Gres-Q-L. (Para os curiosos que querem
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saber como se diz "PostgreSQL", um arquivo de <20>udio est<73> dispon<6F>vel).
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O PostgreSQL <20> um sistema de banco de dados objeto-relacional que tem
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as caracter<65>sticas de sistemas de bancos de dados comerciais
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tradicionais com melhoramentos encontrados nos sistemas SGBDs de
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pr<70>xima gera<72><61>o. PostgreSQL <20> livre e o c<>digo-fonte completo est<73>
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dispon<6F>vel.
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O desenvolvimento do PostgreSQL <20> feito por um grupo de
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desenvolvedores volunt<6E>rios (na sua maioria) espalhados pelo mundo e
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que se comunicam via Internet. <20> um projeto da comunidade e n<>o <20>
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controlado por nenhuma empresa. Para se envolver, veja a FAQ do
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desenvolvedor em http://www.postgresql.org/docs/faqs.FAQ_DEV.html
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Postgres <20> um apelido para o PostgreSQL amplamente utilizado. Era o
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nome original do projeto em Berkeley e dentre os outros apelidos <20> o
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preferido. Se voc<6F> acha 'PostgreSQL' dif<69>cil de pronunciar, diga
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apenas 'Postgres'.
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1.2) Quem controla o PostgreSQL?
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Se voc<6F> est<73> procurando por um mantenedor, comit<69> central ou empresa
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controladora do PostgreSQL, desista --- n<>o h<> um(a). N<>s temos um
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comit<69> core e committers CVS, mas estes grupos s<>o mais para quest<73>es
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administrativas do que controle. O projeto <20> direcionado pela
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comunidade de desenvolvedores e usu<73>rios, que qualquer um pode se
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juntar. Tudo o que voc<6F> precisa <20> se inscrever nas listas de discuss<73>o
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e participar das discuss<73>es. Veja a FAQ do desenvolvedor para obter
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informa<6D><61>es como se envolver com o desenvolvimento do PostgreSQL.
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1.3) Qual <20> a licen<65>a do PostgreSQL?
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O PostgreSQL <20> distribu<62>do sob a licen<65>a BSD cl<63>ssica. Basicamente,
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ela permite que usu<73>rios fa<66>am qualquer coisa com o c<>digo, incluindo
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revender os bin<69>rios sem o c<>digo-fonte. A <20>nica restri<72><69>o <20> que voc<6F>
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n<>o nos responsabilize legalmente por problemas com o programa de
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computador. H<> tamb<6D>m a exig<69>ncia de que esta licen<65>a apare<72>a em todas
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as c<>pias do programa de computador. Aqui est<73> a licen<65>a BSD que
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usamos atualmente:
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PostgreSQL est<73> sujeito a seguinte licen<65>a:
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PostgreSQL Data Base Management System
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Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
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Portions Copyright (c) 1994-1996 Regents of the University of
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California
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Permission to use, copy, modify, and distribute this software and its
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documentation for any purpose, without fee, and without a written
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agreement is hereby granted, provided that the above copyright notice
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and this paragraph and the following two paragraphs appear in all
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copies.
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IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
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FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
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INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND
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ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN
|
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ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
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MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
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PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
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CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
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UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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1.4) Quais plataformas o PostgreSQL pode ser executado?
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Em geral, qualquer plataforma moderna compat<61>vel com Unix deve ser
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capaz de executar o PostgreSQL. As plataformas que foram testadas
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antes do lan<61>amento de uma vers<72>o s<>o listadas nas instru<72><75>es de
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instala<6C><61>o.
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O PostgreSQL tamb<6D>m executa nativamente nos sistemas operacionais
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Microsoft Windows baseados no NT tais como Win200 SP4, WinXP e
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Win2003. Um instalador pr<70>-empacotado est<73> dispon<6F>vel em
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http://pgfoundry.org/projects/pginstaller. Vers<72>es do Windows baseadas
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no MS-DOS (Win95, Win98, WinMe) podem executar o PostgreSQL utilizando
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o Cygwin.
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H<> tamb<6D>m uma vers<72>o para o Novell Netware 6 em
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http://forge.novell.com e uma vers<72>o para OS/2 (eComStation) em
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http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
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SQL&stype=all&sort=type&dir=%2F.
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1.5) Onde eu posso conseguir o PostgreSQL?
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Via navegador web, utilize http://www.postgresql.org/ftp/ e via ftp,
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utilize ftp://ftp.postgresql.org/pub/.
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1.6) Qual <20> a <20>ltima vers<72>o?
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A <20>ltima vers<72>o do PostgreSQL <20> a vers<72>o 8.2.5.
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N<>s planejamos lan<61>ar vers<72>es novas a cada ano com vers<72>es corretivas
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em alguns meses.
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1.7) Onde eu posso conseguir suporte?
|
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|
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A comunidade do PostgreSQL fornece assist<73>ncia a muitos de seus
|
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usu<73>rios via e-mail. O principal s<>tio web para inscri<72><69>o nas listas
|
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de e-mail <20> http://www.postgresql.org/community/lists/. As listas
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general e bugs s<>o um bom lugar para in<69>cio.
|
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|
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O principal canal de IRC <20> o #postgresql na Freenode
|
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(irc.freenode.net). Para se conectar voc<6F> pode utilizar o comando Unix
|
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irc -c '#postgresql' "$USER" irc.freenode.net ou utilizar qualquer
|
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outro cliente de IRC. Um canal hisp<73>nico (#postgresql-es) e um franc<6E>s
|
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(#postgresqlfr) tamb<6D>m existem na mesma rede. H<> tamb<6D>m um canal
|
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PostgreSQL na EFNet.
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|
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Uma lista de empresas que prestam suporte comercial est<73> dispon<6F>vel em
|
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http://www.postgresql.org/support/professional_support.
|
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|
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1.8) Como eu informo a exist<73>ncia de um bug?
|
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|
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Visite o formul<75>rio que reporta bugs do PostgreSQL em
|
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http://www.postgresql.org/support/submitbug.
|
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|
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Verifique tamb<6D>m o nosso ftp ftp://ftp.postgresql.org/pub para ver se
|
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h<> uma vers<72>o mais recente do PostgreSQL.
|
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|
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Bugs submetidos utilizando o formul<75>rio ou informado a qualquer lista
|
||||
de discuss<73>o do PostgreSQL tipicamente gera uma das seguintes
|
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respostas:
|
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* N<>o <20> um bug e o porqu<71>
|
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* <20> um bug conhecido e j<> est<73> na lista de AFAZERES
|
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* O bug foi corrigido na vers<72>o atual
|
||||
* O bug foi corrigido mas n<>o foi empacotado em um vers<72>o oficial
|
||||
* Um pedido foi feito para obter informa<6D><61>es detalhadas:
|
||||
+ Sistema Operacional
|
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+ Vers<72>o do PostgreSQL
|
||||
+ Exemplo de teste que reproduz o bug
|
||||
+ Informa<6D><61>es sobre depura<72><61>o
|
||||
+ Sa<53>da reconstituidora de vest<73>gios (backtrace) do depurador
|
||||
* O bug <20> novo. O seguinte pode ocorrer:
|
||||
+ Uma corre<72><65>o <20> criada e ser<65> inclu<6C>da na pr<70>xima vers<72>o
|
||||
+ O bug n<>o pode ser corrigido imediatamente e <20> adicionado a
|
||||
lista de AFAZERES
|
||||
|
||||
1.9) Como eu posso saber quais s<>o os bugs conhecidos ou funcionalidades
|
||||
ausentes?
|
||||
|
||||
O PostgreSQL suporta um subconjunto extendido do SQL:2003. Veja nossa
|
||||
lista de AFAZERES que cont<6E>m bugs conhecidos, funcionalidades ausentes
|
||||
e planos futuros.
|
||||
|
||||
Uma solicita<74><61>o de funcionalidade geralmente resulta em uma das
|
||||
seguintes respostas:
|
||||
* A funcionalidade j<> est<73> na lista de AFAZERES
|
||||
* A funcionalidade n<>o <20> desej<65>vel porque:
|
||||
+ Ela duplica uma funcionalidade existente que j<> segue o
|
||||
padr<64>o SQL
|
||||
+ A funcionalidade aumentar<61> a complexidade do c<>digo mas
|
||||
adicionar<61> pouco benef<65>cio
|
||||
+ A funcionalidade ser<65> insegura ou n<>o-confi<66>vel
|
||||
* A nova funcionalidade <20> adicionada a lista de AFAZERES
|
||||
|
||||
O PostgreSQL n<>o utiliza sistema de acompanhamento de bugs porque n<>s
|
||||
achamos mais eficiente responder diretamente o e-mail e manter a lista
|
||||
de AFAZERES atualizada. Na pr<70>tica, bugs n<>o duram muito no programa;
|
||||
e bugs que afetam uma grande quantidade de usu<73>rios s<>o corrigidos
|
||||
rapidamente. O <20>nico lugar para encontrar todas as mudan<61>as, melhorias
|
||||
e corre<72><65>es em uma vers<72>o do PostgreSQL <20> ler as mensagens de log do
|
||||
CVS. At<41> mesmo as notas de lan<61>amento n<>o listam todas as mudan<61>as
|
||||
feitas no programa.
|
||||
|
||||
1.10) Que documenta<74><61>o est<73> dispon<6F>vel?
|
||||
|
||||
O PostgreSQL inclui vasta documenta<74><61>o, incluindo um manual extenso,
|
||||
p<>ginas de manuais (man pages) e alguns exemplos teste. Veja o
|
||||
diret<65>rio /doc. Voc<6F> tamb<6D>m pode pesquisar os manuais online em
|
||||
http://www.postgresql.org/docs.
|
||||
|
||||
H<> dois livros sobre PostgreSQL dispon<6F>veis online em
|
||||
http://www.postgresql.org/docs/books/awbook.html e
|
||||
http://www.commandprompt.com/ppbook/. H<> uma lista de livros sobre
|
||||
PostgreSQL dispon<6F>veis para compra. Um dos mais populares <20> o do Korry
|
||||
Douglas. Uma lista de an<61>lise sobre os livros pode ser encontrada em
|
||||
http://www.postgresql.org/docs/books/. H<> tamb<6D>m uma cole<6C><65>o de
|
||||
artigos t<>cnicos sbore PostgreSQL em
|
||||
http://www.postgresql.org/docs/techdocs/.
|
||||
|
||||
O programa cliente de linha de comando psql tem alguns comandos \d
|
||||
para mostrar informa<6D><61>es sobre tipos, operadores, fun<75><6E>es, agrega<67><61>es,
|
||||
etc. - utilize \? para mostrar os comandos dispon<6F>veis.
|
||||
|
||||
Nosso s<>tio web cont<6E>m ainda mais documenta<74><61>o.
|
||||
|
||||
1.11) Como eu posso aprender SQL?
|
||||
|
||||
Primeiro, considere os livros espec<65>ficos sobre PostgreSQL mencionados
|
||||
acima. Muitos de nossos usu<73>rios gostam do The Practical SQL Handbook,
|
||||
Bowman, Judith S., et al., Addison-Wesley. Outros do The Complete
|
||||
Reference SQL, Groff et al., McGraw-Hill.
|
||||
|
||||
H<> tamb<6D>m bons tutoriais dispon<6F>veis online:
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm
|
||||
* http://sqlcourse.com
|
||||
* http://www.w3schools.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12) Como posso submeter uma corre<72><65>o (patch) ou me juntar a equipe de
|
||||
desenvolvimento?
|
||||
|
||||
Veja a FAQ do Desenvolvedor.
|
||||
|
||||
1.13) Como <20> o PostgreSQL comparado a outros SGBDs?
|
||||
|
||||
H<> v<>rias maneiras de se medir um software: funcionalidades,
|
||||
performance, confiabilidade, suporte e pre<72>o.
|
||||
|
||||
Funcionalidades
|
||||
PostgreSQL tem muitas caracter<65>sticas presentes em muitos SGBDs
|
||||
comerciais como transa<73><61>es, subconsultas, gatilhos, vis<69>es,
|
||||
integridade referencial de chave estrangeira e bloqueio (lock)
|
||||
sofisticado. N<>s temos algumas funcionalidades que eles n<>o
|
||||
tem, como tipos definidos pelo usu<73>rio, heran<61>a, regras e
|
||||
controle de concorr<72>ncia de m<>ltiplas vers<72>es para reduzir
|
||||
bloqueios (locks).
|
||||
|
||||
Performance
|
||||
A performance do PostgreSQL <20> compar<61>vel a outros bancos de
|
||||
dados comerciais e de c<>digo livre. Ele <20> mais r<>pido em
|
||||
algumas coisas, mais lento em outras. Nossa performance <20>
|
||||
geralmente +/- 10% comparada a de outros bancos de dados.
|
||||
|
||||
Confiabilidade
|
||||
N<>s sabemos que um SGBD deve ser confi<66>vel ou ele <20> in<69>til. N<>s
|
||||
empenhamos em lan<61>ar vers<72>es bem testadas, de c<>digo est<73>vel e
|
||||
que tenha o m<>nimo de bugs. Cada vers<72>o tem no m<>nimo um m<>s de
|
||||
teste em vers<72>o beta, e nosso hist<73>rico de vers<72>es mostra que
|
||||
n<>s podemos fornecer vers<72>es est<73>veis e s<>lidas que est<73>o
|
||||
prontas para uso em produ<64><75>o. N<>s acreditamos que somos
|
||||
comparados a nosso favor com outros sistemas de bancos de dados
|
||||
nessa <20>rea.
|
||||
|
||||
Suporte
|
||||
Nossas listas de discuss<73>o fornecem contato com um grupo de
|
||||
desenvolvedores e usu<73>rios para ajudar a resolver muitos
|
||||
problemas encontrados. Enquanto n<>s n<>o podemos garantir o
|
||||
conserto, SGBDs comerciais nem sempre fornecem tamb<6D>m. Com
|
||||
acesso direto aos desenvolvedores, a comunidade de usu<73>rios,
|
||||
manuais e o c<>digo fonte faz com que o suporte do PostgreSQL
|
||||
seja superior ao de outros SGBDs. H<> suporte comercial por
|
||||
incidente dispon<6F>veis para aqueles que precisam de um. (Veja
|
||||
se<73><65>o 1.7 da FAQ).
|
||||
|
||||
Pre<72>o
|
||||
N<>s somos livres para uso dele tanto comercial quanto n<>o
|
||||
comercial. Voc<6F> pode adicionar nosso c<>digo ao seu produto sem
|
||||
limita<74><61>es, exceto aquelas descritas na nossa licen<65>a BSD
|
||||
mencionada acima.
|
||||
|
||||
1.14) O PostgreSQL gerenciar<61> mudan<61>as no hor<6F>rio devido ao hor<6F>rio de ver<65>o
|
||||
em v<>rios pa<70>ses?
|
||||
|
||||
Mudan<61>as no hor<6F>rio de ver<65>o dos USA foram inclu<6C>das nas vers<72>es 8.0
|
||||
.[4+] do PostgreSQL e em todas as vers<72>es grandes, i.e. 8.1. Mudan<61>as
|
||||
no Canad<61> e Austr<74>lia Oeste foram inclu<6C>das na 8.0.[10+], 8.1.[6+] e
|
||||
em todas as vers<72>es grandes subsequentes. Vers<72>es do PostgreSQL
|
||||
anteriores a 8.0 utilizam o banco de dados de zona hor<6F>ria do sistema
|
||||
operacional para informa<6D><61>es sobre hor<6F>rio de ver<65>o.
|
||||
_________________________________________________________________
|
||||
|
||||
Perguntas sobre Clientes
|
||||
|
||||
2.1) Quais interfaces est<73>o dispon<6F>veis para PostgreSQL?
|
||||
|
||||
A instala<6C><61>o do PostgreSQL inclui somente as interfaces C e C
|
||||
embutida. Todas as outras interfaces s<>o projetos independentes que
|
||||
podem ser obtidos separadamente; sendo separados permitem que eles
|
||||
tenham suas pr<70>prias datas de lan<61>amento e time de desenvolvedores.
|
||||
|
||||
Algumas linguagens de programa<6D><61>o como PHP incluem uma interface para
|
||||
PostgreSQL. Interfaces para linguagens como Perl, TCL, Python e muitas
|
||||
outras est<73>o dispon<6F>veis em http://www.pgfoundry.org.
|
||||
|
||||
2.2) Quais ferramentas est<73>o dispon<6F>veis para utilizar o PostgreSQL com
|
||||
p<>ginas Web?
|
||||
|
||||
Uma boa introdu<64><75>o para p<>ginas web que utilizam bancos de dados pode
|
||||
ser vista em: http://www.webreview.com
|
||||
|
||||
Para integra<72><61>o na Web, PHP (http://www.php.net) <20> uma excelente
|
||||
interface.
|
||||
|
||||
Para casos complexos, muitos usam a Interface Perl e DBD::Pg com
|
||||
CGI.pm ou mod_perl.
|
||||
|
||||
2.3) O PostgreSQL tem interfaces gr<67>ficas para iteragir com o usu<73>rio?
|
||||
|
||||
H<> um vasto n<>mero de Ferramentas Gr<47>ficas (GUI), que est<73>o
|
||||
dispon<6F>veis para o PostgreSQL, comerciais e de desenvolvedores de
|
||||
c<>digo aberto. Uma lista detalhada pode ser encontrada em Documenta<74><61>o
|
||||
da Comunidade PostgreSQL
|
||||
_________________________________________________________________
|
||||
|
||||
Perguntas Administrativas
|
||||
|
||||
3.1) Como eu instalo o PostgreSQL em um local diferente de /usr/local/pgsql?
|
||||
|
||||
Especifique a op<6F><70>o --prefix quando executar o configure.
|
||||
|
||||
3.2) Como eu controlo conex<65>es de outras m<>quinas?
|
||||
|
||||
Por padr<64>o, o PostgreSQL s<> permite conex<65>es da m<>quina local
|
||||
utilizando soquetes de dom<6F>nio Unix ou conex<65>es TCP/IP. Outras
|
||||
m<>quinas n<>o poder<65>o conectar-se a menos que voc<6F> modifique
|
||||
listen_addresses no postgresql.conf, habilite a autentica<63><61>o por
|
||||
m<>quina modificando o arquivo $PGDATA/pg_hba.conf e reinicie o
|
||||
servidor PostgreSQL.
|
||||
|
||||
3.3) Como eu ajusto o servidor de banco de dados para obter uma performance
|
||||
melhor?
|
||||
|
||||
H<> tr<74>s grandes <20>reas para melhorar a performance em potencial:
|
||||
|
||||
Mudan<61>a de Consultas
|
||||
Isto involve modificar consultas para obter melhor performance:
|
||||
|
||||
+ Cria<69><61>o de <20>ndices, incluir express<73>es e <20>ndices parciais
|
||||
+ Utiliza<7A><61>o o COPY ao inv<6E>s de m<>ltiplos comandos INSERTs
|
||||
+ Agrupamento de m<>ltiplos comandos em uma <20>nica transa<73><61>o para
|
||||
diminuir a despesa com efetiva<76><61>es (commit)
|
||||
+ Utiliza<7A><61>o do CLUSTER quando recuperar v<>rios registros de um
|
||||
<20>ndice
|
||||
+ Utiliza<7A><61>o do LIMIT para retornar um subconjunto da sa<73>da da
|
||||
consulta
|
||||
+ Utiliza<7A><61>o de Consultas preparadas
|
||||
+ Utiliza<7A><61>o de ANALYZE para manter as estat<61>sticas do
|
||||
otimizador corretas
|
||||
+ Utiliza<7A><61>o regular do VACUUM ou pg_autovacuum
|
||||
+ Remo<6D><6F>o de <20>ndices durante grande mudan<61>a de dados
|
||||
|
||||
Configura<72><61>o do Servidor
|
||||
Um grande n<>mero de configura<72><61>es que afetam a performance.
|
||||
Para obter detalhes adicionais, veja Administration
|
||||
Guide/Server Run-time Environment/Run-time Configuration para
|
||||
listagem completa, e para coment<6E>rios veja
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_co
|
||||
nf_e.html e
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
|
||||
|
||||
Sele<6C><65>o do Hardware
|
||||
O efeito do hardware na performance <20> detalhado em
|
||||
http://www.powerpostgresql.com/PerfList/ e
|
||||
http://momjian.us/main/writings/pgsql/hw_performance/index.html
|
||||
.
|
||||
|
||||
3.4) Quais caracter<65>sticas de depura<72><61>o est<73>o dispon<6F>veis?
|
||||
|
||||
H<> muitas vari<72>veis de configura<72><61>o do servidor log_* que habilitam a
|
||||
exibi<62><69>o de consultas e estat<61>sticas que podem ser muito <20>teis para
|
||||
depura<72><61>o e medidas de performance.
|
||||
|
||||
3.5) Por que eu recebo "Sorry, too many clients" quando eu tento conectar?
|
||||
|
||||
Voc<6F> atingiu o limite padr<64>o de 100 sess<73>es. Voc<6F> precisa aumentar o
|
||||
limite do servidor PostgreSQL, que diz quantos processos servidor
|
||||
concorrentes ele pode iniciar, alterando o valor max_connections no
|
||||
postgresql.conf e reiniciando o postmaster.
|
||||
|
||||
3.6) Qual <20> o processo de atualiza<7A><61>o do PostgreSQL?
|
||||
|
||||
Veja http://www.postgresql.org/support/versioning para discuss<73>o geral
|
||||
sobre atualiza<7A><61>es e
|
||||
http://www.postgresql.org/docs/current/static/install-upgrading.html
|
||||
para instru<72><75>es espec<65>ficas.
|
||||
|
||||
3.7) Que tipo de hardware eu devo usar?
|
||||
|
||||
Por causa do hardware de PC ser em sua maioria compat<61>vel, pessoas
|
||||
tendem a acreditar que todos os hardwares de PC s<>o de mesma
|
||||
qualidade. N<>o <20> verdade. ECC RAM, SCSI e placas m<>e de qualidade s<>o
|
||||
mais confi<66>veis e t<>m uma melhor performance do que hardwares mais
|
||||
baratos. O PostgreSQL executar<61> em quase todo hardware, mas se a
|
||||
confiabilidade e a performance forem importantes <20> prudente pesquisar
|
||||
sobre as op<6F><70>es de hardware. Nossas listas de discuss<73>o podem ser
|
||||
usadas para discutir op<6F><70>es de hardware e dilemas.
|
||||
_________________________________________________________________
|
||||
|
||||
Perguntas Operacionais
|
||||
|
||||
4.1) Como eu fa<66>o um SELECT somente dos primeiros registros de uma consulta?
|
||||
Um registro rand<6E>mico?
|
||||
|
||||
Para obter somente alguns registros, se voc<6F> sabe o n<>mero de
|
||||
registros necess<73>rios ao executar o SELECT utilize o LIMIT. Se um
|
||||
<20>ndice corresponde no ORDER BY <20> poss<73>vel que a consulta toda n<>o
|
||||
tenha que ser executada. Se voc<6F> n<>o sabe o n<>mero de registros ao
|
||||
executar o SELECT, utilize um cursor e o FETCH.
|
||||
|
||||
Para obter um registro rand<6E>mico, utilize:
|
||||
SELECT col
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1;
|
||||
|
||||
4.2) Como eu descubro quais tabelas, <20>ndices, bancos de dados e usu<73>rios
|
||||
est<73>o definidos? Como eu vejo as consultas utilizadas pelo psql para
|
||||
mostr<74>-los?
|
||||
|
||||
Utilize o comando \dt para ver tabelas no psql. Para obter uma lista
|
||||
completa dos comandos no psql voc<6F> pode utilizar \?. Alternativamente,
|
||||
voc<6F> pode ler o c<>digo-fonte do psql no arquivo
|
||||
pgsql/src/bin/psql/describe.c, ele cont<6E>m os comandos SQL que geram a
|
||||
sa<73>da para os comandos de contrabarra do psql. Voc<6F> tamb<6D>m pode
|
||||
iniciar o psql com a op<6F><70>o -E para que as consultas utilizadas para
|
||||
executar os comandos que voc<6F> informou seja exibida. O PostgreSQL
|
||||
tamb<6D>m fornece uma inteface compat<61>vel com SQL do INFORMATION SCHEMA
|
||||
que voc<6F> pode consultar para obter informa<6D><61>o sobre o banco de dados.
|
||||
|
||||
H<> tamb<6D>m tabelas do sistema que come<6D>am com pg_ que os descrevem
|
||||
tamb<6D>m.
|
||||
|
||||
Utilizando o psql -l listar<61> todos os bancos de dados.
|
||||
|
||||
Veja tamb<6D>m o arquivo pgsql/src/tutorial/syscat.source. Ele ilustra
|
||||
muitos dos comandos SELECTs necess<73>rios para obter informa<6D><61>o das
|
||||
tabelas de sistema do banco de dados.
|
||||
|
||||
4.3) Como voc<6F> muda o tipo de dado de uma coluna?
|
||||
|
||||
Mudar o tipo de dado de uma coluna pode ser feito facilmente na vers<72>o
|
||||
8.0 ou superior com ALTER TABLE ALTER COLUMN TYPE.
|
||||
|
||||
Em vers<72>es anteriores, fa<66>a isso:
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN col_nova novo_tipo_dado;
|
||||
UPDATE tab SET col_nova = CAST(col_antiga AS novo_tipo_dado);
|
||||
ALTER TABLE tab DROP COLUMN col_antiga;
|
||||
COMMIT;
|
||||
|
||||
Voc<6F> pode ent<6E>o querer fazer um VACUUM FULL tab para recuperar o
|
||||
espa<70>o em disco utilizado pelos registros expirados.
|
||||
|
||||
4.4) Qual <20> o tamanho m<>ximo de um registro, uma tabela e um banco de dados?
|
||||
|
||||
Estes s<>o os limites:
|
||||
|
||||
Tamanho m<>ximo de um banco de dados? ilimitado (existem bancos de
|
||||
dados de 32 TB)
|
||||
Tamanho m<>ximo de uma tabela? 32 TB
|
||||
Tamanho m<>ximo de um registro? 400 GB
|
||||
Tamanho m<>ximo de um campo? 1 GB
|
||||
N<>mero m<>ximo de registros em uma tabela? ilimitado
|
||||
N<>mero m<>ximo de colunas em uma tabela? 250-1600 dependendo dos tipos
|
||||
das colunas
|
||||
N<>mero m<>ximo de <20>ndices em uma tabela? ilimitado
|
||||
|
||||
<20> claro, que eles n<>o s<>o ilimitados, mas limitados ao espa<70>o em disco
|
||||
dispon<6F>vel e espa<70>o em mem<65>ria/swap. A Performance ser<65> penalizada
|
||||
quando estes valores se tornarem grandes.
|
||||
|
||||
O tamanho m<>ximo de uma tabela com 32 TB n<>o requer suporte a arquivos
|
||||
grandes do sistema operacional. Tabelas grandes s<>o armazenadas como
|
||||
m<>ltiplos arquivos de 1 GB ent<6E>o o limite do sistema de arquivos n<>o <20>
|
||||
importante.
|
||||
|
||||
O tamanho m<>ximo de uma tabela, o tamanho de um registro e o n<>mero
|
||||
m<>ximo de colunas podem ser quadruplicados aumentando-se o tamanho
|
||||
padr<64>o do bloco para 32k. O tamanho m<>ximo de uma tabela pode tamb<6D>m
|
||||
ser aumentado utilizando particionamento de tabela.
|
||||
|
||||
Uma limita<74><61>o <20> que <20>ndices n<>o podem ser criados em colunas maiores
|
||||
do que 2.000 caracteres. Felizmente, tais <20>ndices s<>o raramente
|
||||
necess<73>rios. Unicidade <20> melhor garantida por um <20>ndice de uma fun<75><6E>o
|
||||
de um hash MD5 de uma coluna longa, e indexa<78><61>o de texto longo permite
|
||||
a busca de palavras dentro da coluna.
|
||||
|
||||
4.5) Quanto espa<70>o em disco <20> necess<73>rio para armazenar dados de um arquivo
|
||||
texto?
|
||||
|
||||
Um banco de dados PostgreSQL ir<69> requerer at<61> cinco vezes a quantidade
|
||||
de espa<70>o requerida para armazenar dados em um arquivo texto.
|
||||
|
||||
Como um exemplo, considere um arquivo com 100.000 linhas contendo um
|
||||
inteiro e uma descri<72><69>o em cada linha. Suponha que o tamanho m<>dio da
|
||||
descri<72><69>o <20> de vinte bytes. O arquivo ter<65> 2,8 MB. O tamanho do
|
||||
arquivo do banco de dados PostgreSQL que cont<6E>m esses dados pode ser
|
||||
estimado em 5,2 MB:
|
||||
24 bytes: cada cabe<62>alho de registro (aproximadamente)
|
||||
24 bytes: um campo int e um campo texto
|
||||
+ 4 bytes: ponteiro na p<>gina para a tupla
|
||||
-------------------------------------------
|
||||
52 bytes por registro
|
||||
|
||||
O tamanho de uma p<>gina de dados no PostgreSQL <20> 8192 bytes (8 KB), ent<6E>o:
|
||||
|
||||
8192 bytes por p<>gina
|
||||
------------------------ = 158 registros por p<>gina do banco de dados (arredondado para baixo)
|
||||
52 bytes por registro
|
||||
|
||||
100000 registros de dados
|
||||
---------------------------- = 633 p<>ginas do banco de dados (arredondadopara cima)
|
||||
158 registros por p<>gina
|
||||
|
||||
633 p<>ginas do banco de dados * 8192 bytes por p<>gina = 5.185.536 bytes (5,2MB)
|
||||
|
||||
<20>ndices n<>o requerem muito espa<70>o, mas cont<6E>m dados que foram
|
||||
indexados, ent<6E>o eles podem ocupar algum espa<70>o.
|
||||
|
||||
NULLs s<>o armazenados como bitmaps, ent<6E>o eles utilizam muito pouco
|
||||
espa<70>o.
|
||||
|
||||
4.6) Por que minhas consultas est<73>o lentas? Por que elas n<>o est<73>o utilizando
|
||||
meus <20>ndices?
|
||||
|
||||
<20>ndices n<>o s<>o utilizados por toda consulta. <20>ndices s<>o utilizados
|
||||
somente se a tabela <20> maior do que um tamanho m<>nimo, e a consulta
|
||||
seleciona somente uma pequena porcentagem dos registros da tabela.
|
||||
Isto porque o acesso rand<6E>mico ao disco causado pela busca indexada
|
||||
pode ser mais lento do que uma leitura ao longo da tabela ou busca
|
||||
sequencial.
|
||||
|
||||
Para determinar se um <20>ndice deveria ser utilizado, o PostgreSQL deve
|
||||
ter estat<61>sticas sobre a tabela. Estas estat<61>sticas s<>o coletadas
|
||||
utilizando o VACUUM ANALYZE ou simplesmente o ANALYZE. Utilizando
|
||||
estat<61>sticas, o otimizador sbae quantos registros est<73>o na tabela, e
|
||||
pode melhor determinar se <20>ndices deveriam ser utilizados.
|
||||
Estat<61>sticas tamb<6D>m s<>o <20>teis para determinar a ordem de jun<75><6E>o <20>tima
|
||||
e m<>todos de jun<75><6E>o. Cole<6C><65>o de estat<61>sticas deveriam ser feitas
|
||||
periodicamente a medida que o conte<74>do da tabela muda.
|
||||
|
||||
<20>ndices n<>o s<>o normalmente utilizados para ORDER BY ou para fazer
|
||||
jun<75><6E>es. Uma busca sequencial seguido por uma ordena<6E><61>o expl<70>cita <20>
|
||||
geralmente mais r<>pida do que uma busca indexada em uma tabela grande.
|
||||
Contudo, LIMIT combinado com ORDER BY frequentemente utilizar<61> <20>ndice
|
||||
porque somente uma pequena por<6F><72>o da tabela ser<65> retornada.
|
||||
|
||||
Se voc<6F> acredita que o otimizador est<73> incorreto ao escolher uma busca
|
||||
sequencial, utilize SET enable_seqscan TO 'off' e execute a consulta
|
||||
novamente para ver se uma busca indexada <20> realmente mais r<>pida.
|
||||
|
||||
Ao utilizar operadores curinga tais como LIKE ou ~, <20>ndices podem ser
|
||||
utilizados somente em algumas condi<64><69>es:
|
||||
* O in<69>cio da cadeia de caracteres da busca deve ser iniciar com uma
|
||||
cadeia de caracteres, i.e.
|
||||
+ modelos LIKE n<>o devem iniciar com %.
|
||||
+ modelos ~ (express<73>es regulares) devem iniciar com ^.
|
||||
* A cadeia de caracteres utilizada na busca n<>o pode iniciar com a
|
||||
classe de caracteres e.g. [a-e].
|
||||
* Busca que n<>o diferenciam mai<61>sculas de min<69>sculas tais como ILIKE
|
||||
e ~* n<>o utilizam <20>ndices. Em vez disso, utilize <20>ndice de
|
||||
express<73>o, que <20> descrito na se<73><65>o 4.8.
|
||||
* O idioma padr<64>o C deve ser usando durante o initdb porque n<>o <20>
|
||||
poss<73>vel saber o pr<70>ximo caracter em idiomas que n<>o sejam o C.
|
||||
Voc<6F> pode criar um <20>ndice especial text_pattern_ops para tais
|
||||
casos que funcionam somente para indexa<78><61>o com LIKE. Tamb<6D>m <20>
|
||||
poss<73>vel utilizar indexa<78><61>o de busca textual para buscas por
|
||||
palavras.
|
||||
|
||||
Em vers<72>es anteriores a 8.0, <20>ndices frequentemente n<>o podem ser
|
||||
utilizados a menos que os tipos de dados correspondam aos tipos de
|
||||
coluna do <20>ndice. Isto era particularmente verdadeiro para <20>ndices de
|
||||
coluna int2, int8 e numeric.
|
||||
|
||||
4.7) Como eu vejo como o otimizador de consulta est<73> avaliando a minha
|
||||
consulta?
|
||||
|
||||
Veja o comando EXPLAIN no manual.
|
||||
|
||||
4.8) Como eu fa<66>o buscas com express<73>es regulares e buscas com express<73>es
|
||||
regulares sem diferenciar mai<61>sculas de min<69>sculas? Como eu utilizo um <20>ndice
|
||||
para buscas que n<>o diferenciam mai<61>sculas de min<69>sculas?
|
||||
|
||||
O operador ~ faz avalia<69><61>o de express<73>es regulares, e ~* faz avalia<69><61>o
|
||||
n<>o sens<6E>vel a mai<61>sculas de express<73>es regulares. A variante n<>o
|
||||
sens<6E>vel a mai<61>sculas do LIKE <20> chamada de ILIKE.
|
||||
|
||||
Compara<72><61>es de igualdade n<>o sens<6E>veis a mai<61>sculas s<>o normalmente
|
||||
expressadas como:
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
|
||||
Isso n<>o ir<69> utilizar o <20>ndice padr<64>o. Contudo, se voc<6F> criar um
|
||||
<20>ndice de express<73>o, ele ser<65> utilizado:
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
|
||||
Se o <20>ndice acima <20> criado como UNIQUE, embora a coluna possa
|
||||
armazenar caracteres mai<61>sculos e min<69>sculos, ele n<>o pode ter valores
|
||||
id<69>nticos que diferem apenas em letras mai<61>sculas e min<69>sculas. Para
|
||||
for<6F>ar uma letra mai<61>scula ou min<69>scula a ser armazenada na coluna,
|
||||
utilize uma restri<72><69>o CHECK ou um gatilho.
|
||||
|
||||
4.9) Em uma consulta, como eu detecto se um campo <20> NULL? Como eu posso
|
||||
concatenar poss<73>veis NULLs? Como eu posso ordenar por um campo que <20> NULL ou
|
||||
n<>o?
|
||||
|
||||
Voc<6F> testa a coluna com IS NULL e IS NOT NULL, como a seguir:
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
|
||||
Para concatenar com poss<73>veis NULLs, utilize COALESCE(), assim:
|
||||
SELECT COALESCE(col1, '') || COALESCE(col2, '')
|
||||
FROM tab
|
||||
|
||||
Para ordenar pelo status NULL, utilize os modificadores IS NULL e IS
|
||||
NOT NULL na sua cl<63>usula ORDER BY. Coisas que s<>o verdadeiro ser<65>o
|
||||
ordenadas acima das coisas que s<>o falso, ent<6E>o a consulta a seguir
|
||||
ir<69> colocar entradas NULL no in<69>cio da lista de resultados:
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
|
||||
4.10) Qual <20> a diferen<65>a entre os v<>rios tipos de dado de caracteres?
|
||||
|
||||
Tipo Nome Interno Observa<76><61>o
|
||||
VARCHAR(n) varchar tamanho especifica o tamanho m<>ximo, sem
|
||||
preenchimento
|
||||
CHAR(n) bpchar preenchimento em branco para comprimento fixo
|
||||
espec<65>fico
|
||||
TEXT text nenhum limite superior espec<65>fico no comprimento
|
||||
BYTEA bytea vetor de bytes de comprimento vari<72>vel (seguro a byte
|
||||
nulo)
|
||||
"char" char um caracter
|
||||
|
||||
Voc<6F> ver<65> o nome interno quando examinar o cat<61>logo do sistema e em
|
||||
algumas mensagens de erro.
|
||||
|
||||
Os primeiros quatro tipos acima s<>o do tipo "varlena" (i.e., os
|
||||
primeiros quatro bytes no disco s<>o o comprimento seguido pelos
|
||||
dados). Consequentemente o espa<70>o atual utilizado <20> ligeiramente maior
|
||||
do que o tamanho declarado. Contudo, valores longos s<>o tamb<6D>m
|
||||
sujeitos a compress<73>o, ent<6E>o o espa<70>o em disco pode tamb<6D>m ser bem
|
||||
menor do que o esperado.
|
||||
VARCHAR(n) <20> melhor quando est<73> armazenando cadeias de caracteres de
|
||||
comprimento vari<72>vel e h<> um limite de tamanho desta cadeia. TEXT <20>
|
||||
para cadeias de caracteres de comprimento ilimitado, com o m<>ximo de
|
||||
um gigabyte.
|
||||
|
||||
CHAR(n) <20> para armazenar cadeias de caracteres que s<>o todas do mesmo
|
||||
tamanho. CHAR(n) preenche com espa<70>os em branco at<61> o tamanho
|
||||
especificado, enquanto o VARCHAR(n) armazena somente os caracteres
|
||||
fornecidos. BYTEA <20> para armazenar dados bin<69>rios, particularmente
|
||||
valores que incluem bytes NULL. Todos os tipos descritos aqui tem
|
||||
caracter<65>sticas de performance similares.
|
||||
|
||||
4.11.1) Como eu crio um campo serial/auto incremento?
|
||||
|
||||
PostgreSQL suporta o tipo de dados SERIAL. Ele cria automaticamente
|
||||
uma sequ<71>ncia. Por exemplo:
|
||||
CREATE TABLE pessoa (
|
||||
id SERIAL,
|
||||
nome TEXT
|
||||
);
|
||||
|
||||
<20> automaticamente traduzido em:
|
||||
CREATE SEQUENCE pessoa_id_seq;
|
||||
CREATE TABLE pessoa (
|
||||
id INT4 NOT NULL DEFAULT nextval('pessoa_id_seq'),
|
||||
nome TEXT
|
||||
);
|
||||
|
||||
Sequ<71>ncias automaticamente criadas s<>o nomeadas como
|
||||
<tabela>_<colunaserial>_seq, onde tabela e colunaserial s<>o os nomes
|
||||
da tabela e da coluna serial, respectivamente. Veja a p<>gina sobre
|
||||
create_sequence no manual para obter informa<6D><61>es adicionais sobre
|
||||
sequ<71>ncias.
|
||||
|
||||
4.11.2) Como eu consigo o valor de um campo SERIAL?
|
||||
|
||||
A maneira mais simples de obter o pr<70>ximo valor SERIAL de uma
|
||||
sequ<71>ncia <20> com RETURNING. Utilizando o exemplo da tabela em 4.11.1,
|
||||
ele ficaria assim:
|
||||
INSERT INTO pessoa (nome) VALUES ('Blaise Pascal') RETURNING id;
|
||||
|
||||
Voc<6F> tamb<6D>m pode chamar nextval() e utilizar o valor no INSERT ou
|
||||
chamar currval() ap<61>s o INSERT.
|
||||
|
||||
4.11.3) currval() n<>o lida com condi<64><69>o de corrida com outros usu<73>rios?
|
||||
|
||||
N<>o. currval() retorna o valor atual atribuido pela sua sess<73>o, e n<>o
|
||||
por todas as sess<73>es.
|
||||
|
||||
4.11.4) Por que os n<>meros da minha sequ<71>ncia n<>o s<>o reutilizados quando uma
|
||||
transa<73><61>o <20> abortada? Por que h<> intervalos nos n<>meros da minha
|
||||
sequ<71>ncia/coluna SERIAL?
|
||||
|
||||
Para melhorar a concorr<72>ncia, valores da sequ<71>ncia s<>o atribu<62>dos a
|
||||
transa<73><61>es correntes e n<>o s<>o travados at<61> que a transa<73><61>o seja
|
||||
finalizada. Isso causa intervalos na numera<72><61>o por causa de transa<73><61>es
|
||||
abortadas.
|
||||
|
||||
4.12) O que <20> um OID? O que <20> um CTID?
|
||||
|
||||
Se uma tabela <20> criada com WITH OIDS, cada registro recebe um OID
|
||||
<20>nico. OIDs s<>o automaticamente atribu<62>dos como inteiros de 4 bytes
|
||||
que s<>o <20>nicos ao longo de toda instala<6C><61>o. Contudo, eles s<>o
|
||||
limitados em 4 bilh<6C>es e, ent<6E>o, os OIDs come<6D>am a ser duplicados. O
|
||||
PostgreSQL utiliza OIDs para ligar as tabelas do sistema.
|
||||
|
||||
Para numerar registros nas tabelas do usu<73>rios, <20> melhor utilizar
|
||||
SERIAL ao inv<6E>s de OIDs porque sequ<71>ncias SERIAL s<>o <20>nicas somente em
|
||||
uma tabela; e s<>o menos prop<6F>cias a atingir o limite. SERIAL8 est<73>
|
||||
dispon<6F>vel para armazenar valores de sequ<71>ncias com oito bytes.
|
||||
|
||||
CTIDs s<>o utilizados para identificar registros f<>sicos espec<65>ficos
|
||||
com valores de block e deslocamento. CTIDs mudam ap<61>s registros serem
|
||||
modificados ou recarregados. Eles s<>o utilizados por <20>ndices para
|
||||
apontar registros f<>sicos.
|
||||
|
||||
4.13) Por que eu recebo o erro "ERROR: Memory exhausted in AllocSetAlloc()"?
|
||||
|
||||
Voc<6F> provavelmente est<73> sem mem<65>ria virtual no seu sistema, ou o seu
|
||||
n<>cleo (kernel) tem um limite baixo para certos recursos. Tente isto
|
||||
antes de iniciar o servidor PostgreSQL:
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
Dependendo da sua shell, somente um desses comando ter<65> sucesso, mas
|
||||
ele definir<69> o segmento de dados do seu processo com um limite maior e
|
||||
talvez permita que a consulta seja feita. Este comando <20> aplicado ao
|
||||
processo atual e todos os subprocessos criados depois do comando ser
|
||||
executado. Se voc<6F> tiver problemas com o cliente SQL porque o processo
|
||||
servidor retornou muitos dados, tente-o antes de iniciar o cliente.
|
||||
|
||||
4.14) Como eu informo qual vers<72>o do PostgreSQL eu estou utilizando?
|
||||
|
||||
No psql, digite SELECT version();
|
||||
|
||||
4.15) Como eu crio uma coluna que conter<65> por padr<64>o a hora atual?
|
||||
|
||||
Utilize CURRENT_TIMESTAMP:
|
||||
CREATE TABLE teste (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP);
|
||||
|
||||
4.16) Como eu fa<66>o uma jun<75><6E>o externa (outer join)?
|
||||
|
||||
PostgreSQL suporta jun<75><6E>es externas utilizando a sintaxe padr<64>o do
|
||||
SQL. Aqui temos dois exemplos:
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
|
||||
or
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
|
||||
Essas duas consultas ind<6E>nticas juntam t1.col com t2.col, e tamb<6D>m
|
||||
retornam qualquer registro que n<>o foi juntado em t1 (aqueles que n<>o
|
||||
combinaram com t2). Uma jun<75><6E>o a direita RIGHT adicionaria registros
|
||||
que n<>o foram juntados da tabela t2. Uma jun<75><6E>o completa (FULL)
|
||||
retornaria os registros combinados mais todos os registros n<>o
|
||||
combinados de t1 e t2. A palavra OUTER <20> opcional e <20> assumida nas
|
||||
jun<75><6E>es LEFT, RIGHT e FULL. Jun<75><6E>es ordin<69>rias s<>o chamadas jun<75><6E>es
|
||||
internas (INNER).
|
||||
|
||||
4.17) Como eu fa<66>o consultas utilizando m<>ltiplos bancos de dados?
|
||||
|
||||
N<>o h<> outra maneira de consultar um banco de dados caso ele n<>o seja
|
||||
o atual. Porque o PostgreSQL carrega cat<61>logos do sistema espec<65>ficos
|
||||
do banco de dados, <20> incerto como uma consulta em banco de dados
|
||||
distintos pode se comportar.
|
||||
|
||||
contrib/dblink permite consultas em bancos de dados distintos
|
||||
utilizando chamadas de fun<75><6E>es. <20> claro, que um cliente pode fazer
|
||||
conex<65>es simult<6C>neas em bancos de dados diferentes e juntar os
|
||||
resultados no cliente.
|
||||
|
||||
4.18) Como eu retorno m<>ltiplos registros ou colunas de uma fun<75><6E>o?
|
||||
|
||||
<20> f<>cil utilizando fun<75><6E>es que retornam conjunto,
|
||||
http://www.postgresql.org/docs/techdocs.17.
|
||||
|
||||
4.19) Por que eu obtenho erros "relation with OID ###### does not exist" ao
|
||||
acessar tabelas tempor<6F>rias em fun<75><6E>es PL/PgSQL?
|
||||
|
||||
Em vers<72>es do PostgreSQL < 8.3, PL/PgSQL armazena o conte<74>do da
|
||||
fun<75><6E>o, e o efeito indesejado <20> que se uma fun<75><6E>o PL/PgSQL acessa uma
|
||||
tabela tempor<6F>ria, e aquela tabela <20> removida e criada novamente, e a
|
||||
fun<75><6E>o <20> chamada novamente, a fun<75><6E>o ir<69> falhar porque o conte<74>do
|
||||
armazenado da fun<75><6E>o ainda apontar<61> para a tabela tempor<6F>ria antiga. A
|
||||
solu<6C><75>o <20> utilizar o EXECUTE para acesso a tabelas tempor<6F>rias no
|
||||
PL/PgSQL. Isto ir<69> fazer com que a consulta seja avaliada toda vez.
|
||||
|
||||
Este problema n<>o ocorre no PostgreSQL 8.3 ou superior.
|
||||
|
||||
4.20) Quais solu<6C><75>es de replica<63><61>o est<73>o dispon<6F>veis?
|
||||
|
||||
Embora "replica<63><61>o" seja um termo simples, h<> v<>rias tecnologias para
|
||||
fazer replica<63><61>o, com vantagens e desvantagens para cada um.
|
||||
|
||||
Replica<63><61>o mestre/escravo permite que um mestre receba consultas de
|
||||
leitura e escrita, enquanto os escravos s<> podem aceitar
|
||||
leitura/consultas SELECT. A solu<6C><75>o mais popular de replica<63><61>o
|
||||
mestre-escravo para PostgreSQL dispon<6F>vel livremente <20> Slony-I.
|
||||
|
||||
Replica<63><61>o com m<>ltiplos mestres permite que consultas leitura/escrita
|
||||
sejam enviadas para m<>ltiplos computadores replicadores. Esta
|
||||
capacidade tamb<6D>m tem um s<>rio impacto na performance por causa da
|
||||
necessidade de sincronizar as mudan<61>as entre os servidores. PGCluster
|
||||
<20> a solu<6C><75>o mais popular dispon<6F>vel livremente para PostgreSQL.
|
||||
|
||||
H<> tamb<6D>m solu<6C><75>es de replica<63><61>o comerciais e baseadas em hardware
|
||||
dispon<6F>veis que suportam uma variedade de modelos de replica<63><61>o.
|
||||
|
||||
4.21) Por que os nomes de minhas tabelas e colunas n<>o s<>o reconhecidos em
|
||||
minha consulta? Por que as mai<61>sculas n<>o s<>o preservadas?
|
||||
|
||||
A causa mais comum de nomes desconhecidos <20> o uso de aspas ao redor
|
||||
dos nomes da tabela ou coluna durante a cria<69><61>o da tabela. Ao utilizar
|
||||
aspas, nomes de tabela e coluna (chamados de identificadores) s<>o
|
||||
armazenados como especificado, significando que voc<6F> deve utilizar
|
||||
aspas quando se referir aos nomes na consulta. Algumas interfaces,
|
||||
como pgAdmin, automaticamente colocam aspas nos identificadores
|
||||
durante a cria<69><61>o da tabela. Ent<6E>o, para identificadores serem
|
||||
reconhecidos, voc<6F> deve:
|
||||
* Evitar colocar aspas no identificador ao criar tabelas
|
||||
* Utilizar somente caracteres min<69>sculos em identificadores
|
||||
* Colocar aspas em identificadores ao referenci<63>-los nas consultas
|
||||
@ -1,801 +0,0 @@
|
||||
|
||||
PostgreSQL 常<><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FAQ<41><51>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2007 年 1 <20> 30 <20><> <20><><EFBFBD><EFBFBD> 17:37:01 EST
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2007 年 2 <20> 1 <20><> <20><><EFBFBD> 12:55:04 CST
|
||||
|
||||
<20><><EFBFBD>维<EFBFBD><E7BBB4>人<EFBFBD><E4BABA><EFBFBD>Bruce Momjian (pgman@candle.pha.pa.us)
|
||||
<20><><EFBFBD><EFBFBD>维<EFBFBD><E7BBB4>人<EFBFBD><E4BABA><EFBFBD>Daojing.Zhou<6F><75>doudou586@gmail.com<6F><6D>
|
||||
|
||||
<20><><EFBFBD>档<EFBFBD><E6A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ.html<6D><6C><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>平<EFBFBD><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.postgresql.org/docs/faq/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
常<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.1)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>该<EFBFBD><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.2)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>管<EFBFBD>PostgreSQL <20><>
|
||||
1.3)PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.4)PostgreSQL<51><4C>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>平<EFBFBD><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.5)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C>
|
||||
1.6)<29><><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.7)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.8)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4>个BUG<55><47><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.9)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解已<E8A7A3><E5B7B2><EFBFBD> BUG <20><>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.10)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>档<EFBFBD><E6A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.11)<29><><EFBFBD>该<EFBFBD><E8AFA5> <20><><EFBFBD><EFBFBD><EFBFBD> SQL <20><>
|
||||
1.12)<29><><EFBFBD><EFBFBD><EFBFBD>交补<E4BAA4><E8A1A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.13)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.14)PostgreSQL <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>家<EFBFBD><E5AEB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><EFBFBD>端<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
2.1)<29>们<EFBFBD><E4BBAC>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20>交<EFBFBD><E4BAA4><EFBFBD>
|
||||
2.2)<29><><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD>以<EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD> Web 页<><E9A1B5><EFBFBD><EFBFBD>
|
||||
2.3)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD>形<EFBFBD><E5BDA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
系<EFBFBD><EFBFBD>管<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.1)<29><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD> /usr/local/pgsql 以<><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.2)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.3)<29><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.4)PostgreSQL <20><><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.5)为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Sorry, too many clients<74> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.6)PostgreSQL<51><4C>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9>
|
||||
3.7)(使<><E4BDBF>PostgreSQL)<29><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD>硬件 <20><>
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD>头<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.2)
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>psql<71><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD>令并<E4BBA4><E5B9B6><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC>
|
||||
4.3) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD>
|
||||
4.4) <20><><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD>个表<E4B8AA><E8A1A8><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.5) <20><><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD>
|
||||
4.6) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询没<E8AFA2><E6B2A1><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
4.7) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>估<EFBFBD><E4BCB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD>
|
||||
4.8) <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD>索<EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.9) <20><><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD>为
|
||||
NULL<4C><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>论<EFBFBD><E8AEBA>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>NULL<4C><4C><EFBFBD><EFBFBD>
|
||||
4.10) <20><><EFBFBD><EFBFBD>符类<E7ACA6><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.1) <20><><EFBFBD> <20><>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5>
|
||||
4.11.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.3) <20><><EFBFBD>使<EFBFBD><E4BDBF> currval() <20><>导<EFBFBD><E5AFBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.4) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.12) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OID<49><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CTID <20><>
|
||||
4.13) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>误信<E8AFAF><E4BFA1><EFBFBD>ERROR: Memory exhausted in
|
||||
AllocSetAlloc()<29><><EFBFBD>
|
||||
4.14) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.15) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA>个缺<E4B8AA><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5>
|
||||
4.16) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>outer join<69><6E><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>
|
||||
4.17) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>
|
||||
4.18) <20><><EFBFBD><EFBFBD>让<EFBFBD><E8AEA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.19) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>PL/PgSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>临<EFBFBD><E4B8B4>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>误信<E8AFAF><E4BFA1><EFBFBD>relation
|
||||
with OID ##### does not exist<73><74><EFBFBD>
|
||||
4.20) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.21) 为<><E4B8BA><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD>示<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
常<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.1)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>该<EFBFBD><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL 读<><E8AFBB> Post-Gres-Q-L<><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>称为Postgres
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>载声<E8BDBD><E5A3B0><EFBFBD>件<EFBFBD><E4BBB6> MP3 <20> <20><><EFBFBD> <20>
|
||||
|
||||
PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>代 DBMS 系<><E7B3BB><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD>强<EFBFBD><E5BCBA><EFBFBD><EFBFBD><EFBFBD>PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>费<EFBFBD><E8B4B9><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>代<EFBFBD> <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个社<E4B8AA>
|
||||
<20><><EFBFBD><EFBFBD>项<EFBFBD><E9A1B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被任<E8A2AB><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>请<EFBFBD><E8AFB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FAQ<41><51>
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html
|
||||
|
||||
1.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><>寻<EFBFBD><E5AFBB>PostgreSQL<51><4C><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
央<><E5A4AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>---<2D> 为<><E4B8BA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD>确<EFBFBD><E7A1AE><EFBFBD>个
|
||||
<20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>CVS管<53><E7AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD>设<EFBFBD><E8AEBE>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>管<EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>对PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL项<4C><E9A1B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>人<EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>人<EFBFBD>社<EFBFBD><E7A4BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>订<EFBFBD><E8AEA2><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>讨论
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD>详<EFBFBD><E8AFA6> <20><><EFBFBD>人<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD> (Developer's FAQ)
|
||||
<20><><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.3)PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>?
|
||||
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>BSD<53><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD>许<EFBFBD><E8AEB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>以<EFBFBD><E4BBA5><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>代<EFBFBD> <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> 软件<E8BDAF><E4BBB6><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们追<E4BBAC><E8BFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>责任<E8B4A3><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD>中
|
||||
须<><E9A1BB><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD>声<EFBFBD><E5A3B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD>们<EFBFBD>使<EFBFBD><E4BDBF><EFBFBD>BSD<53><44>声<EFBFBD><E5A3B0>容<EFBFBD><E5AEB9>
|
||||
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>管<EFBFBD>系<EFBFBD><E7B3BB>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>c<EFBFBD><63>1996-2005<30><35>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>c<EFBFBD><63>1994-1996
|
||||
<20> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>Portions copyright (c) 1996-2005,PostgreSQL Global Development Group
|
||||
Portions Copyright (c) 1994-6 Regents of the University of
|
||||
California<69><61>
|
||||
|
||||
<20>许为任<E4B8BA><E4BBBB><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD>档<EFBFBD><E6A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>费<EFBFBD>
|
||||
<20><><EFBFBD> 并<><E5B9B6><EFBFBD> 须<><E9A1BB>署<EFBFBD> <20><>
|
||||
<20><>产<EFBFBD><E4BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>声<EFBFBD><E5A3B0><EFBFBD><EFBFBD>段以<E6AEB5><E4BBA5><EFBFBD><EFBFBD><EFBFBD>两段<E4B8A4><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>Permission to use, copy, modify, and distribute this software and
|
||||
its documentation for any purpose, without fee, and without a written
|
||||
agreement is hereby granted, provided that the above copyright notice
|
||||
and this paragraph and the following two paragraphs appear in all
|
||||
copies.<2E><>
|
||||
|
||||
<20><>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF><EFBFBD><EFBFBD>
|
||||
<20>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD>档<EFBFBD>导<EFBFBD><E5AFBC><EFBFBD>对任<E5AFB9><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>伴<EFBFBD><E4BCB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD>责任<E8B4A3><E4BBBB><EFBFBD><EFBFBD>使<EFBFBD> <20><>大<EFBFBD><E5A4A7>
|
||||
<20>已<EFBFBD><E5B7B2>建议<E5BBBA><E8AEAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD><E5A4B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
|
||||
PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
|
||||
DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS
|
||||
SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA
|
||||
HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.<2E><>
|
||||
|
||||
<20> <20><>大<EFBFBD><E5A4A7><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>份软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> <20><>大<EFBFBD><E5A4A7>
|
||||
<20>没<EFBFBD>责任<E8B4A3><E4BBBB><EFBFBD>维<EFBFBD><E7BBB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>强<EFBFBD><E5BCBA>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
||||
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
|
||||
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
|
||||
CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
|
||||
UPDATES, ENHANCEMENTS, OR MODIFICATIONS.<2E><>
|
||||
|
||||
1.4)PostgreSQL <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>平<EFBFBD><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>说<EFBFBD><E8AFB4><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对 UNIX <20><>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD>平<EFBFBD><E5B9B3><EFBFBD>
|
||||
|
||||
PostgreSQl<51><6C><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>微软Windows-NT<4E><54><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Win2000
|
||||
SP4<50><34>WinXP <20> Win2003<30><33>已<EFBFBD><E5B7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://pgfoundry.org/projects/pginstaller<65><72>载<EFBFBD><E8BDBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>MSDOS<4F>Windows<77><73><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD> <20><>Win95<39><35>Win98<39><38>WinMe<4D><65><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Cygwin模<6E><E6A8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个为Novell Netware 6<><36><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://forge.novell.com<6F><6D><EFBFBD><EFBFBD><EFBFBD>为OS/2(eComStation)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
|
||||
SQL&stype=all&sort=type&dir=%2F <20><>载<EFBFBD>
|
||||
|
||||
1.5) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.postgresql.org/ftp/<2F><>载<EFBFBD><E8BDBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FTP<54><50><EFBFBD><EFBFBD>
|
||||
ftp://ftp.PostgreSQL.org/pub/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>载<EFBFBD>
|
||||
|
||||
1.6) <20><><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 8.2.1 <20>
|
||||
|
||||
<20>们计<E4BBAC><E8AEA1><EFBFBD>年<EFBFBD><E5B9B4><EFBFBD><EFBFBD><EFBFBD>个主<E4B8AA><E4B8BB><EFBFBD>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 个<><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.7) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL社<4C><E7A4BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表为<E8A1A8><E4B8BA>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>帮<EFBFBD><E5B8AE><EFBFBD><EFBFBD>订<EFBFBD><E8AEA2><EFBFBD>件<EFBFBD>表<EFBFBD>主
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://www.postgresql.org/community/lists/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>General <20>
|
||||
Bug<75><67>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
主<><E4B8BB><EFBFBD>IRC<52><43><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FreeNode(irc.freenode.net)<29>#postgresql<71><6C>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF>UNIX<49><58><EFBFBD><EFBFBD>irc<72><63><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> irc -c '#postgresql'
|
||||
"$USER" irc.freenode.net <20><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>IRC客<43><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>个PostgreSQL<51>西<EFBFBD><E8A5BF><EFBFBD><EFBFBD><EFBFBD>(#postgersql-es)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
(#postgresql-fr)<29><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>EFNET<45><54><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个PostgreSQL<51>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>http://techdocs.postgresql.org/companies.php<68><70>
|
||||
<20><><EFBFBD>
|
||||
|
||||
1.8) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4>个BUG<55><47><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>访<EFBFBD><E8AEBF>
|
||||
http://www.postgresql.org/support/submitbug<75><67>填<EFBFBD>Bug<75><67><EFBFBD><EFBFBD>表<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>访<EFBFBD><E8AEBF>ftp<74><70><EFBFBD><EFBFBD>ftp://ftp.PostgreSQL.org/pub/
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD>补<EFBFBD><E8A1A5><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>使<EFBFBD><E4BDBF>Bug<75>交表<E4BAA4> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C>件<EFBFBD>表<EFBFBD>Bug<75>常<EFBFBD><E5B8B8><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>
|
||||
* <20><>交<EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Bug<75><67><EFBFBD> <20>
|
||||
* <20><>交<EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD>个已<E4B8AA><E5B7B2><EFBFBD>Bug并<67><E5B9B6>已<EFBFBD><E5B7B2><EFBFBD> <20><>TODO<44><4F><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD>表<EFBFBD>
|
||||
* <20><>交<EFBFBD>Bug已<67><E5B7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被修<E8A2AB><E4BFAE><EFBFBD>
|
||||
* <20><>交<EFBFBD>Bug已修<E5B7B2><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>补<EFBFBD><E8A1A5><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6>
|
||||
* 请<><E8AFB7><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>详<EFBFBD><E8AFA6><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD>系<EFBFBD><E7B3BB>
|
||||
+ PostgreSQL<51><4C><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>踪<EFBFBD><E8B8AA><EFBFBD><EFBFBD>
|
||||
* <20><>交<EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD>
|
||||
+ <20>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA>补<EFBFBD><E8A1A5>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个主<E4B8AA><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD> <20><>TODO<44><4F><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD>表<EFBFBD>
|
||||
|
||||
1.9) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解已<E8A7A3><E5B7B2><EFBFBD> BUG <20><>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD> SQL:2003 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD>TODO
|
||||
<20>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>解已<E8A7A3><E5B7B2>Bug<75>表<EFBFBD><E8A1A8>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>请<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* 该<><E8AFA5><EFBFBD>已<EFBFBD> <20><>TODO<44><4F><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD>表<EFBFBD>
|
||||
* 该<><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>须<EFBFBD><E9A1BB><EFBFBD><EFBFBD> 为<><E4B8BA>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD>SQL<51> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ 该<><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大大<E5A4A7><E5A4A7><EFBFBD> 代<> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>带<EFBFBD><E5B8A6><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD>微<EFBFBD><E5BEAE>足<EFBFBD><E8B6B3><EFBFBD>
|
||||
+ 该<><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
* 该<><E8AFA5><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD> <20><>TODO<44><4F><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD>表<EFBFBD>
|
||||
|
||||
PostgreSQL<51><4C>使<EFBFBD><E4BDBF>Bug<75><67>踪系<E8B8AA><E7B3BB><EFBFBD><EFBFBD><EFBFBD> 为<>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>TODO任<4F><E4BBBB><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
对影<E5AFB9><E5BDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB>被修<E8A2AB><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>CVS<56><53><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.10) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>档<EFBFBD><E6A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL<51><4C><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD>档<EFBFBD><E6A1A3>主<EFBFBD><E4B8BB><EFBFBD>详<EFBFBD><E8AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>页<EFBFBD><E9A1B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> /doc
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>注<EFBFBD><E6B3A8><EFBFBD><EFBFBD>为 $PGHOME/doc<6F><63><EFBFBD>
|
||||
<20><> <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>线<EFBFBD><E7BABF><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.PostgreSQL.org/d
|
||||
ocs<63>
|
||||
|
||||
<20>两<EFBFBD><E4B8A4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>书<EFBFBD><E4B9A6>线<EFBFBD><E7BABF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://www.PostgreSQL.org/docs/awbook.html <20>
|
||||
http://www.commandprompt.com/ppbook/ <20> <20><><EFBFBD>大<EFBFBD><E5A4A7>PostgreSQL书<4C><E4B9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>购
|
||||
买<><E4B9B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Korry Douglas<61><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://techdocs.PostgreSQL.org/techdocs/bookreviews.php<68><70>
|
||||
<20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD>PostgreSQL书<4C><E4B9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
http://techdocs.PostgreSQL.org/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>
|
||||
|
||||
客<><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>psql<71><6C><EFBFBD><EFBFBD><EFBFBD>以 \d
|
||||
<20><>头<EFBFBD><E5A4B4><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>示<EFBFBD><E7A4BA><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> \?
|
||||
<20><>以<EFBFBD><E4BBA5>示<EFBFBD><E7A4BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD>
|
||||
|
||||
<20>们<EFBFBD> web <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>档<EFBFBD>
|
||||
|
||||
1.11) <20><><EFBFBD>该<EFBFBD><E8AFA5> <20><><EFBFBD><EFBFBD><EFBFBD> SQL <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD>书<EFBFBD><E4B9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Teach Yourself SQL in
|
||||
21 Days, Second Edition<6F><6E><EFBFBD><EFBFBD>详<EFBFBD><E8AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://members.tripod.com/er4ebus/sql/index.htm<74><6D>
|
||||
<20>们<EFBFBD>许<EFBFBD><E8AEB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>欢The Practical SQL Handbook<6F><6B> Bowman, Judith S.
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>Addison-Wesley<65><79><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>欢 The Complete Reference SQL,
|
||||
Groff <20><><EFBFBD><EFBFBD><EFBFBD>McGraw-Hill<6C><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC>
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm
|
||||
* http://sqlcourse.com.
|
||||
* http://www.w3schools.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12)<29><><EFBFBD><EFBFBD><EFBFBD>交补<E4BAA4><E8A1A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
详<><E8AFA6> <20><><EFBFBD>人<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD> (Developer's FAQ) <20>
|
||||
|
||||
1.13)PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>价软件<E8BDAF>好<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>价<EFBFBD> <20><>
|
||||
|
||||
<20><><EFBFBD>
|
||||
PostgreSQL <20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>询<EFBFBD><E8AFA2>触<EFBFBD><E8A7A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们没<E4BBAC><E6B2A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD>继<EFBFBD><E7BBA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类似<E7B1BB><E4BCBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快
|
||||
<20><>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8>
|
||||
+/- 10%<25><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD> <20><>
|
||||
<20>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>须<EFBFBD><E9A1BB><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>没<EFBFBD><E6B2A1><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>认<EFBFBD><E8AEA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>稳<EFBFBD><E7A8B3>代<EFBFBD> <20><><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA> beta
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>示<EFBFBD>们<EFBFBD><E4BBAC>以<EFBFBD><E4BBA5><EFBFBD>稳<EFBFBD><E7A8B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>产使<E4BAA7><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>
|
||||
<20>们<EFBFBD><E4BBAC><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>常大<E5B8B8><E5A4A7><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以帮<E4BBA5><E5B8AE>解<EFBFBD><E8A7A3><EFBFBD>碰<EFBFBD>
|
||||
<20><>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解<EFBFBD><E8A7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软
|
||||
件<><E4BBB6>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解<EFBFBD><E8A7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>群<EFBFBD><E7BEA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>触使PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD>
|
||||
<20><>1.7 <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
价<> <20>
|
||||
<20>们对任<E5AFB9><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>费<EFBFBD><E8B4B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><>以<EFBFBD><E4BBA5><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>产<EFBFBD><E4BAA7><EFBFBD> <20><><EFBFBD>们<EFBFBD>代<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>声<EFBFBD><E5A3B0>声<EFBFBD><E5A3B0> BSD<53><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD>
|
||||
|
||||
1.14) PostgreSQL<51><4C>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>家<EFBFBD><E5AEB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>?
|
||||
|
||||
PostgreSQL 8.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>8.0<EFBFBD><EFBFBD>以<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<EFBFBD><EFBFBD><EFBFBD><EFBFBD>身<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><EFBFBD>端<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
2.1) <20>们<EFBFBD><E4BBAC>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>交<EFBFBD><E4BAA4><EFBFBD>
|
||||
|
||||
PostgreSQL(缺<><E7BCBA><EFBFBD><EFBFBD>)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>C<EFBFBD><43><EFBFBD><EFBFBD><EFBFBD><EFBFBD>C<EFBFBD><43><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>项<EFBFBD><E9A1B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>载<EFBFBD><E8BDBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>项<EFBFBD><E9A1B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD>
|
||||
<20><><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>语
|
||||
<20><><EFBFBD><EFBFBD>PHP<48><50><EFBFBD>访<EFBFBD><E8AEBF>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Perl<72>TCL<43>Python以<6E><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://gborg.postgresql.org<72><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Drivers/Interfaces<65><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
并<><E5B9B6><EFBFBD><EFBFBD><EFBFBD>Internet<65><74>容<EFBFBD><E5AEB9>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
2.2) <20><><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD>以<EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD> Web 页<><E9A1B5><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.webreview.com<6F>
|
||||
|
||||
对<><E5AFB9> Web <20><><EFBFBD><EFBFBD>PHP <20><><EFBFBD><EFBFBD>个<EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.php.net/<2F>
|
||||
|
||||
对<><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD> Perl <20><><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF>CGI.pm<70>DBD::Pg <20> mod_perl <20>
|
||||
|
||||
2.3)PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD>形<EFBFBD><E5BDA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>GUI<55><49>形工<E5BDA2><E5B7A5>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD>
|
||||
PostgreSQL社<4C><E7A4BE><EFBFBD>档<EFBFBD><E6A1A3><EFBFBD>个详<E4B8AA><E8AFA6><EFBFBD><EFBFBD>表<EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
系<EFBFBD><EFBFBD>管<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.1)<29><><EFBFBD> <20><><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD> /usr/local/pgsql 以<><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> configure <20><><EFBFBD> <20><> --prefix <20>项<EFBFBD>
|
||||
|
||||
3.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
缺<><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD>许<EFBFBD><E8AEB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> unix <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>TCP/IP<49><50><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD>件postgresql.conf中
|
||||
<20>listen_addresses<65><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD>件$PGDATA/pg_hba.conf<6E><66><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> host-based
|
||||
<20><><EFBFBD>身份认<E4BBBD><E8AEA4><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.3) <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>个主<E4B8AA><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD>:
|
||||
|
||||
+ <20>建索<E5BBBA><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
+ 使<><E4BDBF>COPY<50><59><EFBFBD><EFBFBD>代<EFBFBD><E4BBA3><EFBFBD><EFBFBD>个Insert<72><74><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD>个SQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD>个索<E4B8AA><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>CLUSTER<45><52>
|
||||
+ <20><><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>LIMIT<49><54>
|
||||
+ 使<><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>Prepared Query)<29><>
|
||||
+ 使<><E4BDBF>ANALYZE以<45><E4BBA5><EFBFBD>精确<E7B2BE><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1>
|
||||
+ <20><><EFBFBD>使<EFBFBD><E4BDBF> VACUUM <20> pg_autovacuum
|
||||
+ <20><><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建索<E5BBBA><E7B4A2><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置
|
||||
<20>置<EFBFBD>件postgres.conf中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>设置<E8AEBE><E7BDAE><EFBFBD><EFBFBD>影<EFBFBD><E5BDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
管<><E7AEA1><EFBFBD><EFBFBD>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD><E7BDAE>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解<EFBFBD><E8A7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.varlena.com/varlena/GeneralBits/Tid
|
||||
bits/annotated_conf_e.html <20>
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html<6D>
|
||||
|
||||
硬件<E7A1AC><E4BBB6><EFBFBD><EFBFBD>
|
||||
计<><E8AEA1><EFBFBD><EFBFBD>硬件对<E4BBB6><E5AFB9><EFBFBD><EFBFBD><EFBFBD>影<EFBFBD><E5BDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://candle.pha.pa.us/main/writings/pgsql/hw_performance/inde
|
||||
x.html <20> http://www.powerpostgresql.com/PerfList/<2F>
|
||||
|
||||
3.4)PostgreSQL<51><4C><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD>类似 log_*
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD><E7BDAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
|
||||
3.5) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Sorry, too many
|
||||
clients<74><73>已<EFBFBD>太<EFBFBD><E5A4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>表示<E8A1A8><E7A4BA> 已达<E5B7B2><E8BEBE>缺<EFBFBD>100个并<E4B8AA><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE>postgres
|
||||
ql.conf<6E>件<EFBFBD><E4BBB6><EFBFBD>max_connections<6E><73><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD> postmaster<65><72><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>postmaster<65>
|
||||
|
||||
3.6)PostgreSQL<51><4C>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容 <20><>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>级主<E7BAA7><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Bug修<67><E4BFAE>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
7.4.8 <20>级<EFBFBD><E7BAA7> 7.4.9 <20><><EFBFBD><EFBFBD><EFBFBD> dump <20> restore<72><65><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>软件<E8BDAF><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>该<EFBFBD><E8AFA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>使<EFBFBD><E4BDBF><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>尽快<E5B0BD><E5BFAB>
|
||||
<20><><EFBFBD>尽管<E5B0BD><E7AEA1>次<EFBFBD>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>设计<E8AEBE><E8AEA1><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>Bug<75><67><EFBFBD>代<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL社<4C><E7A4BE>认为<E8AEA4><E4B8BA><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>级<EFBFBD><E7BAA7>
|
||||
|
||||
主<><E4B8BB><EFBFBD><EFBFBD><EFBFBD>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 7.3 <20><> 7.4<EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><EFBFBD>修<EFBFBD><EFBFBD>系<EFBFBD><EFBFBD>表<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>们<EFBFBD><E4BBAC>维<EFBFBD><E7BBB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>导<EFBFBD><E5AFBC><EFBFBD><EFBFBD>dump<6D><70>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>导<EFBFBD><E5AFBC><EFBFBD><EFBFBD>reload<61><64>对主<E5AFB9><E4B8BB><EFBFBD><EFBFBD><EFBFBD>级<EFBFBD><E7BAA7><EFBFBD><EFBFBD>须<EFBFBD><E9A1BB>
|
||||
|
||||
3.7)(使<><E4BDBF>PostgreSQL)<29><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD>硬件 <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD>硬件大<E4BBB6><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD>人们<E4BABA><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD>硬件<E7A1AC>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ECC RAM<41><4D>带<EFBFBD><E5B8A6><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>SCSI
|
||||
<20><>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>质<EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>便<EFBFBD><E4BEBF>货<EFBFBD><E8B4A7><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL
|
||||
<20> <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>硬件<E7A1AC><E4BBB6><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9> <20>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 就<><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 究<><E7A9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>硬件<E7A1AC><E4BBB6>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 硬件<E7A1AC>置<EFBFBD><E7BDAE><EFBFBD>价<EFBFBD><E4BBB7><EFBFBD>讨论<E8AEA8>
|
||||
_________________________________________________________________
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD>头<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询中
|
||||
<20><><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以使<E4BBA5><E4BDBF>LIMIT<49><54><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个索<E4B8AA><E7B4A2><EFBFBD><EFBFBD> ORDER BY中
|
||||
<20><><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>头<EFBFBD> <20><>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD>
|
||||
<20>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>使<EFBFBD><E4BDBF>游<EFBFBD> (cursor)<29>FETCH<43><48><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>使<EFBFBD><E4BDBF>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT cols
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1 ;
|
||||
|
||||
4.2)
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>psql<71><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD>令并<E4BBA4><E5B9B6>示<EFBFBD><E7A4BA>们
|
||||
<20><>
|
||||
|
||||
<20><>psql<71><6C>使<EFBFBD><E4BDBF> \dt <20><>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD>示<EFBFBD><E7A4BA><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解psql中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD>表<EFBFBD><E8A1A8>使<EFBFBD><E4BDBF>\? <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>以<EFBFBD>读 psql <20><><EFBFBD>代<EFBFBD>
|
||||
<20>件pgsql/src/bin/psql/describe.c<><63><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA>psql<71><6C><EFBFBD> <20><>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SQL
|
||||
<20><>令<EFBFBD><E4BBA4><EFBFBD> <20><><EFBFBD><EFBFBD>以带 -E <20>项<EFBFBD><E9A1B9><EFBFBD><EFBFBD> psql<71><6C> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>psql中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD>SQL<51><4C>询语
|
||||
<20><><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>容SQL<51>INFORMATION SCHEMA<4D><41><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD>
|
||||
|
||||
<20><>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以pg_ <20>头<EFBFBD>系<EFBFBD><E7B3BB>表<EFBFBD><E8A1A8><EFBFBD>述<EFBFBD><E8BFB0>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
使<><E4BDBF> psql -l <20>令<EFBFBD><E4BBA4>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
pgsql/src/tutorial/syscat.source<63>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD>举<EFBFBD><E4B8BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>表<EFBFBD><E8A1A8>
|
||||
<20><><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD>SELECT<43><54><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.3) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD>
|
||||
|
||||
<20><>8.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><EFBFBD> ALTER TABLE ALTER
|
||||
COLUMN TYPE <20>
|
||||
|
||||
<20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN new_col new_data_type;
|
||||
UPDATE tab SET new_col = CAST(old_col AS new_data_type);
|
||||
ALTER TABLE tab DROP COLUMN old_col;
|
||||
COMMIT;
|
||||
|
||||
<20><> <20><><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF>VACUUM FULL tab <20>令<EFBFBD><E4BBA4>使系<E4BDBF><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD>
|
||||
|
||||
4.4) <20><><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD>个表<E4B8AA><E8A1A8><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大尺寸<E5B0BA><E5AFB8> <20> <20><><EFBFBD><EFBFBD><EFBFBD>已<EFBFBD><E5B7B2><EFBFBD><EFBFBD> 32TB <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>个表<E4B8AA><E8A1A8>大尺寸<E5B0BA><E5AFB8> 32 TB
|
||||
<20><><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD>大尺寸<E5B0BA><E5AFB8> 1.6 TB
|
||||
<20><>个<EFBFBD>段<EFBFBD><E6AEB5>大尺寸? 1 GB
|
||||
<20><>个表<E4B8AA><E8A1A8>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD>
|
||||
<20><>个表<E4B8AA><E8A1A8>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD> 250-1600 <20><><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>个表<E4B8AA><E8A1A8><EFBFBD>大索<E5A4A7><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>没<EFBFBD><E6B2A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/交<><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>约<EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大影<E5A4A7><E5BDB1>
|
||||
|
||||
<20>表<EFBFBD><E8A1A8>大大<E5A4A7><E5A4A7> 32 TB
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>对<EFBFBD>个<EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD>大表<E5A4A7><E8A1A8><EFBFBD><EFBFBD>个 1 GB <20><>件<EFBFBD><E4BBB6>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>件系<E4BBB6><E7B3BB>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 32K <20><><EFBFBD>大<EFBFBD><E5A4A7>表大<E8A1A8><E5A4A7><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对大<E5AFB9><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2000<30><30>
|
||||
<20><><EFBFBD><EFBFBD>建索<E5BBBA><E7B4A2><EFBFBD>幸<EFBFBD><E5B9B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD>MD5<44><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
并<><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD>许对<E8AEB8><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD>
|
||||
|
||||
4.5) <20><><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>个 Postgres <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD> <20><><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6>身大<E8BAAB><E5A4A7>5<EFBFBD><35><EFBFBD><EFBFBD>
|
||||
<20>空<EFBFBD><E7A9BA><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>设<EFBFBD><E8AEBE><EFBFBD>个 100,000 <20><><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD>述<EFBFBD>
|
||||
<20>设<EFBFBD><E8AEBE><EFBFBD>串<EFBFBD>平<EFBFBD><E5B9B3><EFBFBD>度为20<32><30><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD> <20><> 2.8 MB<4D><42><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件大约<E5A4A7><E7BAA6> 6.4 MB:
|
||||
28 <20><>: <20><><EFBFBD><EFBFBD><EFBFBD>头<EFBFBD><E5A4B4>大约<E5A4A7><E7BAA6><EFBFBD><EFBFBD>
|
||||
24 <20><>: <20><>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD>段
|
||||
+ 4 <20><>: 页<><E9A1B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
----------------------------------------
|
||||
56 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD>页<EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> 8192 <20><> (8 KB)<29><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
8192 <20><><EFBFBD><EFBFBD>页
|
||||
------------------- = 146 <20><>/<2F><><EFBFBD><EFBFBD>页<EFBFBD><E9A1B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
56 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
100000 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
-------------------- = 685 <20><><EFBFBD><EFBFBD>页<EFBFBD><E9A1B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
146 <20><>/<2F><><EFBFBD><EFBFBD>页
|
||||
|
||||
685 <20><><EFBFBD><EFBFBD>页 * 8192 <20><>/页 = 5,611,520 <20><><EFBFBD><EFBFBD>5.6 MB<4D><42>
|
||||
|
||||
索<><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD>被索<E8A2AB><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20><><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD>
|
||||
|
||||
空<><E7A9BA>NULL<4C><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD>
|
||||
|
||||
4.6) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询没<E8AFA2><E6B2A1><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
|
||||
并<><E5B9B6><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD>
|
||||
询<><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> 为索<E4B8BA><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>读<EFBFBD>表<EFBFBD><E8A1A8>顺<EFBFBD><E9A1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>PostgreSQL<51><4C>须<EFBFBD><E9A1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD>以使<E4BBA5>
|
||||
<20> VACUUM ANALYZE<5A><45><EFBFBD> ANALYZE <20><><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
<20><>计<EFBFBD><E8AEA1>对确<E5AFB9><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>顺<EFBFBD><E9A1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
索<><E7B4A2><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ORDER BY
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9>个大表<E5A4A7><E8A1A8><EFBFBD>次顺<E6ACA1><E9A1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> LIMIT <20> ORDER BY
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起使<E8B5B7><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD> 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> 确信PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>顺<EFBFBD><E9A1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD> <20><>以使<E4BBA5><E4BDBF>SET
|
||||
enable_seqscan TO 'off'<27>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD>顺<EFBFBD><E9A1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD> 就<><E5B0B1>以<EFBFBD><E4BBA5><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>个索<E4B8AA><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> LIKE <20> ~ <20><><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>
|
||||
* <20>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>须<EFBFBD><E9A1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>说<EFBFBD><E8AFB4>
|
||||
+ LIKE 模<><E6A8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以 % <20>头<EFBFBD>
|
||||
+ ~ <20><><EFBFBD><EFBFBD><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD>模<EFBFBD><E6A8A1><EFBFBD><EFBFBD>须以 ^ <20>头<EFBFBD>
|
||||
* <20>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>符<EFBFBD>模<EFBFBD><E6A8A1>类<EFBFBD>头<EFBFBD><E5A4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD> [a-e]<5D>
|
||||
* 大<><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ILIKE <20> ~* <20><><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5> 4.8
|
||||
<20><>述<EFBFBD>表达<E8A1A8><E8BEBE>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
* <20><><EFBFBD> initdb <20><><EFBFBD><EFBFBD>须<EFBFBD><E9A1BB><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>设置 C
|
||||
locale<6C><65><EFBFBD> 为系<E4B8BA><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>C locale<6C><65><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>大<EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以<EFBFBD>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD>text_pattern_ops索<73><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>LIKE
|
||||
<20>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
<20><>8.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD>被<EFBFBD><E8A2AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>对int2,int8<74><38><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
4.7) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>估<EFBFBD><E4BCB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>
|
||||
|
||||
<20><> EXPLAIN <20><>页<EFBFBD>
|
||||
|
||||
4.8) <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD>索<EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>符 ~ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ~* <20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>表达<E8A1A8><E8BEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD> LIKE <20><><EFBFBD><EFBFBD>为 ILIKE<4B>
|
||||
|
||||
大<><E5A4A7><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
|
||||
<20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD> <20><>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD>表达<E8A1A8><E8BEBE><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>:
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>述索<E8BFB0><E7B4A2><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD> <20><>UNIQUE约<45><E7BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>段<EFBFBD><E6AEB5>身<EFBFBD>容<EFBFBD><E5AEB9>以<EFBFBD><E4BBA5>
|
||||
<20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>UNIQUE约<45><E7BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF>CHECK约<4B><E7BAA6><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD>触<EFBFBD><E8A7A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.9) <20><><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD>为 NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>确<EFBFBD><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>论<EFBFBD><E8AEBA><EFBFBD>
|
||||
段<><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL <20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> IS NULL <20> IS NOT NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
|
||||
为<><E4B8BA><EFBFBD><EFBFBD>对<EFBFBD><E5AFB9> NULL<4C>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ORDER BY <20><>件<EFBFBD><E4BBB6>使<EFBFBD><E4BDBF> IS NULL<4C> IS NOT
|
||||
NULL 修饰符<E9A5B0><E7ACA6><EFBFBD><EFBFBD>件为<E4BBB6> true <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件为<E4BBB6>false <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
就<><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL <20>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
|
||||
4.10) <20><><EFBFBD><EFBFBD>符类<E7ACA6><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
类<> <20><><EFBFBD><EFBFBD>称 说<>
|
||||
VARCHAR(n) varchar <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>补<EFBFBD><E8A1A5>
|
||||
CHAR(n) bpchar <20><><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD>以空<E4BBA5> <20>补<EFBFBD><E8A1A5>
|
||||
TEXT text 没<><E6B2A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD>
|
||||
BYTEA bytea <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>NULL<4C>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD>许<EFBFBD><E8AEB8><EFBFBD>
|
||||
"char" char <20>个<EFBFBD>符
|
||||
|
||||
<20><>系<EFBFBD><E7B3BB>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>误信<E8AFAF><E4BFA1><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>称<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD>"varlena"<22><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>说<EFBFBD><E8AFB4><EFBFBD><EFBFBD>头<EFBFBD><E5A4B4>个<EFBFBD><E4B8AA>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD>声<EFBFBD><E5A3B0>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以被<E4BBA5>缩<EFBFBD><E7BCA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20><><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
VARCHAR(n) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2><EFBFBD>好<EFBFBD><E5A5BD> TEXT <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>大<EFBFBD><E5A4A7>达 1G左<47><E5B7A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6>符串<E7ACA6>
|
||||
|
||||
CHAR(n) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6> CHAR(n)<29><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
段<><E6AEB5>度以空<E4BBA5> <20>补足<E8A1A5><E8B6B3><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3>段<EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD> <20> VARCHAR(n) <20><><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD> BYTEA <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>尤<EFBFBD><E5B0A4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL <20><>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD>差<EFBFBD><E5B7AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.11.1) <20><><EFBFBD> <20><>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5>
|
||||
|
||||
PostgreSQL <20><><EFBFBD> SERIAL <20><><EFBFBD><EFBFBD>类<EFBFBD><E7B1BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
段<><E6AEB5><EFBFBD><EFBFBD>为SERIAL<41><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
);
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>转<EFBFBD><E8BDAC>为以<E4B8BA><E4BBA5>SQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
|
||||
<20><> create_sequence <20><>页<EFBFBD><E9A1B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD>
|
||||
|
||||
4.11.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> nextval() <20><><EFBFBD><EFBFBD><EFBFBD>对象<E5AFB9><E8B1A1><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个 SERIAL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>精确<E7B2BE><E7A1AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> 4.11.1 <20><><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>伪<EFBFBD> <20><><EFBFBD> <20><>述<EFBFBD><E8BFB0>
|
||||
new_id = execute("SELECT nextval('person_id_seq')");
|
||||
execute("INSERT INTO person (id, name) VALUES (new_id, 'Blaise Pascal')");
|
||||
|
||||
<20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> new_id <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD> person
|
||||
表<><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 注<><E6B3A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD> SEQUENCE 对象<E5AFB9><E8B1A1>称<EFBFBD><E7A7B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<table>_<serialcolumn>_seq<65><71> <20><><EFBFBD> table <20> serialcolumn
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>表<EFBFBD><E8A1A8>称<EFBFBD><E7A7B0><EFBFBD> <20> SERIAL <20>段<EFBFBD><E6AEB5>称<EFBFBD>
|
||||
|
||||
类似<E7B1BB><E4BCBC><EFBFBD><EFBFBD><EFBFBD> SERIAL 对象缺<E8B1A1><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> currval() <20><>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SERIAL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
execute("INSERT INTO person (name) VALUES ('Blaise Pascal')");
|
||||
new_id = execute("SELECT currval('person_id_seq')");
|
||||
|
||||
4.11.3) <20><><EFBFBD>使<EFBFBD><E4BDBF> currval() <20><>导<EFBFBD><E5AFBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>currval() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.11.4) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
|
||||
为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>就<EFBFBD><E5B0B1>导<EFBFBD><E5AFBC><EFBFBD><EFBFBD>常中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.12) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OID <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CTID <20><>
|
||||
|
||||
PostgreSQL
|
||||
<20><>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD>OID<49><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8>使<EFBFBD><E4BDBF>WITHOUT
|
||||
OIDS<44>项<EFBFBD> OID<49>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个4<E4B8AA><34><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OID
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>40亿<30><E4BABF><EFBFBD><EFBFBD>溢<EFBFBD><E6BAA2><EFBFBD><EFBFBD> OID<49><44>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>表<EFBFBD>使<EFBFBD><E4BDBF> OID <20><>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD>系<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD>使<EFBFBD><E4BDBF>SERIAl<41><6C>代<EFBFBD><E4BBA3>OID
|
||||
<20> 为SERIAL<41><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>溢<EFBFBD><E6BAA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SERIAL8<4C><38><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>8<EFBFBD><38><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
CTID <20><><EFBFBD><EFBFBD><EFBFBD> <20><>带<EFBFBD><E5B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>移<EFBFBD><E7A7BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CTID
|
||||
<20><>记<EFBFBD><E8AEB0>被<EFBFBD><E8A2AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>载<EFBFBD><E8BDBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>们<EFBFBD><E4BBAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.13) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>误信<E8AFAF><E4BFA1><EFBFBD>ERROR: Memory exhausted in AllocSetAlloc()<29><><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>对<EFBFBD><E5AFB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
postmaster <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4>
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>
|
||||
shell<6C><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD>设<EFBFBD><E8AEBE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20> <20><><EFBFBD>许<EFBFBD><E8AEB8>让<EFBFBD><E8AEA9>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>SQL客<4C><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD> 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>太<EFBFBD><E5A4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>请<EFBFBD><E8AFB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
客<><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0>令<EFBFBD>
|
||||
|
||||
4.14) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> psql <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SELECT version();<3B>令<EFBFBD>
|
||||
|
||||
4.15) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA>个缺<E4B8AA><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5>
|
||||
|
||||
使<><E4BDBF> CURRENT_TIMESTAMP<4D><50>
|
||||
CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
|
||||
4.16) <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> outer join <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD> <20><> SQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>两个<E4B8A4><E4B8AA><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
|
||||
<20><><EFBFBD>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
|
||||
<20><>两个<E4B8A4>价<EFBFBD><E4BBB7><EFBFBD>询<EFBFBD><E8AFA2> t1.col <20> t2.col <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD><EFBFBD> t1 中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t2 <20><>没<EFBFBD><E6B2A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>RIGHT OUTER
|
||||
JOIN<49><4E><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t2 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FULL OUTER JOIN<49><4E><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t1 <20> t2
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> OUTER <20><>左[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[<5B><>]<5D><><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被称为<E7A7B0><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>INNER JOIN<49><4E><EFBFBD>
|
||||
|
||||
4.17) <20><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>
|
||||
|
||||
没<><E6B2A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20> 为PostgreSQL<51><4C><EFBFBD> 载<><E8BDBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系<EFBFBD><E7B3BB>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20>跨<EFBFBD><E8B7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> <20><><EFBFBD><EFBFBD>模<EFBFBD>contrib/dblink<6E>许<EFBFBD><E8AEB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>跨<EFBFBD><E8B7A8><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><E5AEA2>端<EFBFBD>并<EFBFBD><E5B9B6><EFBFBD><EFBFBD>
|
||||
|
||||
4.18) <20><><EFBFBD><EFBFBD>让<EFBFBD><E8AEA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>记<EFBFBD><E8AEB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD>详<EFBFBD><E8AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://techdocs.postgresql.org/guides/SetReturningFunctions
|
||||
|
||||
4.19) 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>PL/PgSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>临<EFBFBD><E4B8B4>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>误信<E8AFAF><E4BFA1><EFBFBD>relation with
|
||||
OID ##### does not exist<73><74><EFBFBD>
|
||||
|
||||
PL/PgSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>带<EFBFBD><E5B8A6><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个
|
||||
PL/PgSQL
|
||||
<20><><EFBFBD><EFBFBD>访<EFBFBD><E8AEBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个临<E4B8AA><E4B8B4>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>该表被<E8A1A8> <20><>并<EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD>该<EFBFBD><E8AFA5><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>失败<E5A4B1><E8B4A5> <20> 为<><E4B8BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>临<EFBFBD><E4B8B4>表<EFBFBD>解<EFBFBD><E8A7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PL/PgSQL
|
||||
<20><><EFBFBD><EFBFBD>EXECUTE
|
||||
对临<E5AFB9><E4B8B4>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>访<EFBFBD><E8AEBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD><E8A2AB><EFBFBD>解<EFBFBD><E8A7A3>
|
||||
|
||||
4.20) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD>
|
||||
|
||||
主/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>许<EFBFBD><E8AEB8>个主<E4B8AA><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>读/<2F><><EFBFBD><EFBFBD>请<EFBFBD><E8AFB7><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD><E4B8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>/SELECT<43><54>询<EFBFBD><E8AFA2><EFBFBD>请<EFBFBD><E8AFB7> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>费<EFBFBD>主/<2F><>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
Slony-I <20>
|
||||
|
||||
<20><>个主<E4B8AA><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>许<EFBFBD><E8AEB8>读/<2F><><EFBFBD><EFBFBD>请<EFBFBD><E8AFB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>计<EFBFBD><E8AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>带<EFBFBD><E5B8A6><EFBFBD><EFBFBD>严<EFBFBD><E4B8A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD><E5A4B1>Pgcluster<65><72><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 中
|
||||
<20>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD>费<EFBFBD><E8B4B9>载<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>费<EFBFBD><E8B4B9><EFBFBD><EFBFBD><EFBFBD>硬件<E7A1AC><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>模<EFBFBD><E6A8A1>
|
||||
|
||||
4.21) 为<><E4B8BA><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD>示<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>为<EFBFBD><E4B8BA>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8>对表<E5AFB9><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>称为<E7A7B0> <20><>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 大<><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5>软件<E8BDAF><E4BBB6><EFBFBD>pgAdmin<69><6E><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>个<EFBFBD> <20><>符<EFBFBD><E7ACA6><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><>
|
||||
<20><><EFBFBD>为<EFBFBD><E4B8BA><EFBFBD> <20><>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>该<EFBFBD><E8AFA5>
|
||||
* <20><><EFBFBD>建表<E5BBBA><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>符使<E7ACA6><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD>
|
||||
* <20><><EFBFBD> <20><>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* <20><>为<EFBFBD><E4B8BA><EFBFBD><EFBFBD>已<EFBFBD><E5B7B2><EFBFBD><EFBFBD><EFBFBD> <20><>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>询<EFBFBD><E8AFA2>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>符<EFBFBD><E7ACA6>起<EFBFBD><E8B5B7><EFBFBD>
|
||||
@ -1,793 +0,0 @@
|
||||
|
||||
PostgreSQL 常<><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FAQ<41><51>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2007 年 2 <20> 8 <20><> <20><><EFBFBD><EFBFBD> 22:43:13 EST
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2007 年 2 <20> 12 <20><> <20><><EFBFBD><EFBFBD> 12:00:04 CST
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD>Bruce Momjian (pgman@candle.pha.pa.us)
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>(ChaoYi, Kuo)<29><>kuo.chaoyi@gmail.com<6F><6D>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ.html <20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>系統平<E7B5B1><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> http://www.postgresql.org/docs/faq/
|
||||
裡<><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
常<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.1)PostgreSQL <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>該<EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.2)誰<><E8AAB0><EFBFBD><EFBFBD><EFBFBD>管<EFBFBD>PostgreSQL <20><>
|
||||
1.3)PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>
|
||||
1.4)PostgreSQL<51><4C>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系統平<E7B5B1><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.5)<29><><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C>
|
||||
1.6)<29><><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>
|
||||
1.7)<29><><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.8)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD> BUG <20> <20><><EFBFBD><EFBFBD>
|
||||
1.9)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解已<E8A7A3><E5B7B2><EFBFBD> BUG <20><><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.10)<29><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.11)<29><>該<EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD> SQL <20><>
|
||||
1.12)<29><><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.13)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫系統<E7B3BB><E7B5B1>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
1.14)PostgreSQL <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>家<EFBFBD><E5AEB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><EFBFBD>端<EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
2.1)<29><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
2.2)<29><><EFBFBD>麼工<E9BABC><E5B7A5><EFBFBD><EFBFBD>以<EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD> Web <20> <20><><EFBFBD><EFBFBD>
|
||||
2.3)PostgreSQL <20><><EFBFBD>形<EFBFBD><E5BDA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>(GUI)<29><><EFBFBD>
|
||||
|
||||
系統管<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.1)<29><>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD> /usr/local/pgsql 以<><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.2)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.3)<29><>樣調<E6A8A3><E8AABF><EFBFBD><EFBFBD><EFBFBD>庫伺<E5BAAB><E4BCBA><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.4)PostgreSQL 裡<><E8A3A1>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼樣<E9BABC>調試<E8AABF><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.5)<29><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>試<EFBFBD><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Sorry, too many clients<74> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
3.6)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9>
|
||||
3.7)(使<><E4BDBF> PostgreSQL )<29><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD>
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD> 幾<><E5B9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫以<E5BAAB><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> psql
|
||||
裡<><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD>令並顯示<E9A1AF><E7A4BA><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.3) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.4) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.5) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件裡<E4BBB6><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD>
|
||||
4.6) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
4.7) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3>估<EFBFBD><E4BCB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD>
|
||||
4.8) <20><>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>索<EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.9) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢裡<E8A9A2><E8A3A1><EFBFBD><EFBFBD>樣檢測<E6AAA2><E6B8AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
NULL<4C><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>NULL<4C><4C><EFBFBD><EFBFBD>
|
||||
4.10) <20>種<EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.1) <20><>樣<EFBFBD><E6A8A3>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.3) <20><>使<EFBFBD><E4BDBF> currval() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.11.4) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.12) <20><>麼<EFBFBD><E9BABC> OID<49><44><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC> CTID <20><>
|
||||
4.13) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>誤<EFBFBD><E8AAA4><EFBFBD><EFBFBD><EFBFBD>ERROR: Memory exhausted in
|
||||
AllocSetAlloc()<29><><EFBFBD>
|
||||
4.14) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.15) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.16) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>outer join<69><6E><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2>
|
||||
4.17) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD>詢<EFBFBD><E8A9A2>
|
||||
4.18) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.19) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD>使<EFBFBD><E4BDBF> PL/PgSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>誤<EFBFBD><E8AAA4><EFBFBD><EFBFBD><EFBFBD>relation
|
||||
with OID ##### does not exist<73><74><EFBFBD>
|
||||
4.20) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>寫(replication)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
4.21) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD>顯示<E9A1AF>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大寫<E5A4A7><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
常<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.1) PostgreSQL <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>該<EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD> Post-Gres-Q-L<><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>簡稱<E7B0A1><E7A8B1>Postgres
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6> MP3 <20> <20><><EFBFBD> <20>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>統<EFBFBD>業
|
||||
<20><><EFBFBD>庫系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>代 DBMS
|
||||
系統<E7B3BB>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD>強<EFBFBD><E5BCB7><EFBFBD><EFBFBD><EFBFBD>PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>費<EFBFBD><E8B2BB><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>代碼<E4BBA3><E7A2BC><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>網<EFBFBD><E7B6B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>繫<EFBFBD><E7B9AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>社<EFBFBD><E7A4BE><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被任<E8A2AB><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FAQ<41><51>
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html
|
||||
|
||||
1.2) 誰<><E8AAB0><EFBFBD><EFBFBD> PostgreSQL <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼中
|
||||
央<><E5A4AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD>屬<EFBFBD><E5B1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>---<2D> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>CVS管<53><E7AEA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD>設
|
||||
<20><>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>管<EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>人<EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>人<EFBFBD><E4BABA>社<EFBFBD><E7A4BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD>詳<EFBFBD><E8A9B3> <20><><EFBFBD>人<EFBFBD><E4BABA>常<EFBFBD><E5B8B8><EFBFBD> (Developer's FAQ) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.3) PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼?
|
||||
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> BSD <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD> PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>代碼<E4BBA3><E7A2BC><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>身<EFBFBD><E8BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>追訴<E8BFBD><E8A8B4><EFBFBD><EFBFBD>
|
||||
責任<E8B2AC><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD>BSD<53><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9>
|
||||
|
||||
PostgreSQL <20><><EFBFBD>庫管<E5BAAB>系統
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>c<EFBFBD><63>1996-2005<30><35>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>c<EFBFBD><63>1994-1996
|
||||
<20> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>Portions copyright (c) 1996-2005,PostgreSQL Global Development Group
|
||||
Portions Copyright (c) 1994-6 Regents of the University of
|
||||
California<69><61>
|
||||
|
||||
<20>許<EFBFBD><E8A8B1>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>費<EFBFBD><E8B2BB><EFBFBD><EFBFBD>
|
||||
並<><E4B8A6><EFBFBD><EFBFBD><EFBFBD> 簽署<E7B0BD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段以<E6AEB5><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>Permission to use, copy, modify, and distribute this software and
|
||||
its documentation for any purpose, without fee, and without a written
|
||||
agreement is hereby granted, provided that the above copyright notice
|
||||
and this paragraph and the following two paragraphs appear in all
|
||||
copies.<2E><>
|
||||
|
||||
<20><>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>伴<EFBFBD><E4BCB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD>責任<E8B2AC><E4BBBB><EFBFBD><EFBFBD>使<EFBFBD> <20><>大<EFBFBD><E5A4A7>
|
||||
<20>已<EFBFBD><E5B7B2>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD><E5A4B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
|
||||
PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
|
||||
DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS
|
||||
SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA
|
||||
HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.<2E><>
|
||||
|
||||
<20> <20><>大<EFBFBD><E5A4A7><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD>份<EFBFBD><E4BBBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD>責任<E8B2AC><E4BBBB><EFBFBD>維
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>強<EFBFBD><E5BCB7>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
||||
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
|
||||
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
|
||||
CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
|
||||
UPDATES, ENHANCEMENTS, OR MODIFICATIONS.<2E><>
|
||||
|
||||
1.4) PostgreSQL <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系統平<E7B5B1><E5B9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>說<EFBFBD><E8AAAA><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> UNIX <20><>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確測試<E6B8AC>平<EFBFBD><E5B9B3><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>微<EFBFBD><E5BEAE> Windows-NT <20><><EFBFBD><EFBFBD><EFBFBD>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD>
|
||||
Win2000 SP4<50><34>WinXP <20> Win2003<30><33>已製<E5B7B2><E8A3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://pgfoundry.org/projects/pginstaller<65><72><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>MSDOS<4F>Windows<77><73>業
|
||||
系統 <20><>Win95<39><35>Win98<39><38>WinMe<4D><65><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Cygwin模<6E><E6A8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Novell Netware 6 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> http://forge.novell.com
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>OS/2(eComStation)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
|
||||
SQL&stype=all&sort=type&dir=%2F <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.5) <20><><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL<51><4C>
|
||||
|
||||
<20><><EFBFBD>覽<EFBFBD><E8A6BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> http://www.postgresql.org/ftp/ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FTP<54><50><EFBFBD><EFBFBD>
|
||||
ftp://ftp.PostgreSQL.org/pub/ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.6) <20><><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 8.2.3 <20>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>年<EFBFBD><E5B9B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>幾<EFBFBD><E5B9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.7) <20><><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL社<4C><E7A4BE><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>幫<EFBFBD><E5B9AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表<EFBFBD>主<EFBFBD><E4B8BB><EFBFBD>
|
||||
<20><><EFBFBD>
|
||||
http://www.postgresql.org/community/lists/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>General <20>
|
||||
Bug<75><67>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
主<><E4B8BB><EFBFBD>IRC<52> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FreeNode(irc.freenode.net)<29>#postgresql<71><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF> UNIX <20><><EFBFBD><EFBFBD> irc<72><63><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> irc -c '#postgresql'
|
||||
"$USER" irc.freenode.net <20><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD>IRC客<43><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>網絡<E7B6B2><E7B5A1><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20>西<EFBFBD><E8A5BF><EFBFBD> <20><>(#postgersql-es)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
(#postgresql-fr)<29><>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD> EFNET <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20>交<EFBFBD><E4BAA4><EFBFBD> <20><><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD> http://techdocs.postgresql.org/companies.php
|
||||
<20>覽<EFBFBD>
|
||||
|
||||
1.8) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD> BUG <20> <20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>訪<EFBFBD> http://www.postgresql.org/support/submitbug<75><67>填寫 Bug
|
||||
<20><><EFBFBD> <20>表<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD>訪<EFBFBD> ftp <20><><EFBFBD><EFBFBD> ftp://ftp.PostgreSQL.org/pub/
|
||||
檢<><E6AAA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>使<EFBFBD><E4BDBF> Bug <20>交表<E4BAA4> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><>件<EFBFBD>表<EFBFBD> Bug
|
||||
<20>常<EFBFBD><E5B8B8>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* <20><>交<EFBFBD><E4BAA4>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Bug <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Bug <20><><EFBFBD> <20>
|
||||
* <20><>交<EFBFBD><E4BAA4>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD>已<EFBFBD><E5B7B2><EFBFBD> Bug 並<><E4B8A6>已<EFBFBD><E5B7B2><EFBFBD> <20><> TODO <20><><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>表<EFBFBD>
|
||||
* <20><>交<EFBFBD> Bug 已<><E5B7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被修<E8A2AB><E4BFAE><EFBFBD>
|
||||
* <20><>交<EFBFBD> Bug 已修<E5B7B2><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* <20><><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詳細<E8A9B3><E7B4B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD>系統
|
||||
+ PostgreSQL <20><><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD> Bug <20>測試<E6B8AC><E8A9A6><EFBFBD><EFBFBD>
|
||||
+ 調試<E8AABF><E8A9A6><EFBFBD><EFBFBD>
|
||||
+ 調試<E8AABF><E8A9A6>蹤輸<E8B9A4><E8BCB8>
|
||||
* <20><>交<EFBFBD><E4BAA4>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD>
|
||||
+ <20><>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><> Bug <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD> <20><> TODO <20><><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>表<EFBFBD>
|
||||
|
||||
1.9) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解已<E8A7A3><E5B7B2><EFBFBD> BUG <20><><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SQL:2003 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> TODO <20>表<EFBFBD><E8A1A8><EFBFBD>解已<E8A7A3><E5B7B2> Bug
|
||||
<20>表<EFBFBD><E8A1A8><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* 該<><E8A9B2><EFBFBD>已<EFBFBD> <20><> TODO <20><><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>表<EFBFBD>
|
||||
* 該<><E8A9B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD> SQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ 該<><E8A9B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大大<E5A4A7><E5A4A7><EFBFBD> 代碼<E4BBA3><E7A2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>帶<EFBFBD><E5B8B6><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD>微<EFBFBD><E5BEAE>足<EFBFBD><E8B6B3><EFBFBD>
|
||||
+ 該<><E8A9B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
* 該<><E8A9B2><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD> <20><> TODO <20><><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>表<EFBFBD>
|
||||
|
||||
PostgreSQL <20><>使<EFBFBD><E4BDBF> Bug <20><>蹤系統<E7B3BB><E7B5B1><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD> TODO
|
||||
任<><E4BBBB>表總<E8A1A8><E7B8BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD>Bug<75><67><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>影<EFBFBD><E5BDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Bug<75><67>總<EFBFBD><E7B8BD><EFBFBD><EFBFBD>快<EFBFBD>被修<E8A2AB><E4BFAE>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CVS
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.10) <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD>詳細<E8A9B3><E7B4B0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>測試<E6B8AC><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
/doc <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>註<EFBFBD><E8A8BB><EFBFBD><EFBFBD><EFBFBD> $PGHOME/doc<6F><63><EFBFBD> <20><> <20><><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>覽 PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>網<EFBFBD><E7B6B2><EFBFBD><EFBFBD><EFBFBD>http://www.PostgreSQL.org/docs<63>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://www.postgresql.org/docs/books/awbook.html <20>
|
||||
http://www.commandprompt.com/ppbook/ <20> <20><><EFBFBD>大<EFBFBD><E5A4A7> PostgreSQL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>購買<E8B3BC><E8B2B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Korry Douglas 編寫<E7B7A8><E5AFAB><EFBFBD><EFBFBD>
|
||||
http://techdocs.PostgreSQL.org/techdocs/bookreviews.php<68><70> <20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD>
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD>簡<EFBFBD><E7B0A1><EFBFBD> <20><> http://techdocs.PostgreSQL.org/ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
PostgreSQL <20>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>
|
||||
|
||||
客<><E5AEA2>端<EFBFBD><E7ABAF><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>psql<71><6C><EFBFBD><EFBFBD><EFBFBD>以 \d <20><> <20>
|
||||
<20><><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD>顯示<E9A1AF><E7A4BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> \?
|
||||
<20><>以顯示<E9A1AF><E7A4BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD>
|
||||
|
||||
<20><><EFBFBD> web <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
1.11) <20><>該<EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD> SQL <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Teach Yourself SQL in
|
||||
21 Days, Second Edition<6F><6E><EFBFBD><EFBFBD>詳細<E8A9B3><E7B4B0>紹<EFBFBD>網<EFBFBD><E7B6B2><EFBFBD>
|
||||
http://members.tripod.com/er4ebus/sql/index.htm<74><6D> <20><><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The
|
||||
Practical SQL Handbook<6F><6B> Bowman, Judith S.
|
||||
編寫<E7B7A8><E5AFAB>Addison-Wesley<65><79><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> The Complete Reference SQL,
|
||||
Groff 編寫<E7B7A8><E5AFAB>McGraw-Hill <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>網<EFBFBD><E7B6B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm
|
||||
* http://sqlcourse.com.
|
||||
* http://www.w3schools.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12)<29><><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
詳<><E8A9B3> <20><><EFBFBD>人<EFBFBD><E4BABA>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD> (Developer's FAQ) <20>
|
||||
|
||||
1.13) PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫系統<E7B3BB><E7B5B1>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好幾種<E5B9BE><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
|
||||
<20><><EFBFBD>
|
||||
PostgreSQL <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>詢<EFBFBD><E8A9A2>觸<EFBFBD><E8A7B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD>繼<EFBFBD><E7B9BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD>似<EFBFBD><E4BCBC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8> +/-
|
||||
10%<25><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD> <20><>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>測試<E6B8AC><E8A9A6><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>穩<EFBFBD><E7A9A9>代碼<E4BBA3><E7A2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> beta
|
||||
測試<E6B8AC><E8A9A6><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>顯示<E9A1AF><E7A4BA><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD>穩<EFBFBD><E7A9A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常大<E5B8B8><E5A4A7><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以幫<E4BBA5><E5B9AB>解決<E8A7A3>碰<EFBFBD><E7A2B0><EFBFBD>
|
||||
任<><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
總<><E7B8BD><EFBFBD><EFBFBD>解決<E8A7A3><E6B1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD>總<EFBFBD><E7B8BD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>決<EFBFBD><E6B1BA><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>群<EFBFBD><E7BEA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>觸使PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>庫<EFBFBD><E5BAAB><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>業
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以給<E4BBA5><E7B5A6><EFBFBD>給<EFBFBD><E7B5A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>1.7 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD> <20>
|
||||
<20><><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>費<EFBFBD><E8B2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><>以<EFBFBD><E4BBA5><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>裡<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>代碼<E4BBA3><E7A2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD> BSD<53><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD>
|
||||
|
||||
1.14) PostgreSQL <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>家<EFBFBD><E5AEB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>?
|
||||
|
||||
PostgreSQL 8.0<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系統<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
8.0 <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD>身<EFBFBD><E8BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><EFBFBD>端<EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
2.1) <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL (<28> <20><><EFBFBD><EFBFBD><EFBFBD>)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> C <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> C
|
||||
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|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>編<EFBFBD><E7B7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PHP <20><><EFBFBD>訪<EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Perl<72>TCL<43>Python
|
||||
以<><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> http://gborg.postgresql.org 網<><E7B6B2><EFBFBD><EFBFBD><EFBFBD>
|
||||
Drivers/Interfaces <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 並<><E4B8A6><EFBFBD><EFBFBD> Internet <20><>容<EFBFBD><E5AEB9>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
2.2) <20><><EFBFBD>麼工<E9BABC><E5B7A5><EFBFBD><EFBFBD>以<EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD> Web <20> <20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>紹以<E7B4B9><E4BBA5><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.webreview.com<6F>
|
||||
|
||||
<20><><EFBFBD><EFBFBD> Web <20><><EFBFBD><EFBFBD>PHP <20><><EFBFBD><EFBFBD><EFBFBD>極好<E6A5B5><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> http://www.php.net/<2F>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD> Perl <20><><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF> CGI.pm <20> DBD::Pg <20> mod_perl
|
||||
<20>
|
||||
|
||||
2.3)PostgreSQL <20><><EFBFBD>形<EFBFBD><E5BDA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>人<EFBFBD><E4BABA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PostgreSQL<51>GUI <20>形工<E5BDA2><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
PostgreSQL社<4C><E7A4BE><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>詳細<E8A9B3><E7B4B0>表<EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
系統管<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.1)<29><>樣<EFBFBD><E6A8A3><EFBFBD> PostgreSQL <20><><EFBFBD><EFBFBD> /usr/local/pgsql 以<><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> configure <20><> <20><> --prefix <20><><EFBFBD> <20>
|
||||
|
||||
3.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> unix <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> TCP/IP
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> <20><><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD>件 postgresql.conf <20><><EFBFBD>
|
||||
listen_addresses<65><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD>件 $PGDATA/pg_hba.conf <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> host-based <20><><EFBFBD>身份<E8BAAB><E4BBBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD>
|
||||
PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> PostgreSQL 伺<><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
3.3) <20><>樣調<E6A8A3><E8AABF><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5> PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD>:
|
||||
|
||||
+ <20><>建索<E5BBBA><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
+ 使<><E4BDBF> COPY <20><><EFBFBD><EFBFBD>代<EFBFBD><E4BBA3><EFBFBD><EFBFBD><EFBFBD> Insert <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD>SQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>交<EFBFBD><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> CLUSTER<45><52>
|
||||
+ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> LIMIT<49><54>
|
||||
+ 使<><E4BDBF><EFBFBD> 編<><E7B7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2>Prepared Query)<29><>
|
||||
+ 使<><E4BDBF> ANALYZE 以<><E4BBA5><EFBFBD>精確<E7B2BE><E7A2BA><EFBFBD><EFBFBD>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD>
|
||||
+ <20><><EFBFBD>使<EFBFBD><E4BDBF> VACUUM <20> pg_autovacuum
|
||||
+ <20><><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建索<E5BBBA><E7B4A2><EFBFBD><EFBFBD>
|
||||
|
||||
伺<><E4BCBA><EFBFBD><EFBFBD><EFBFBD>置
|
||||
<20>置<EFBFBD>件 postgres.conf <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>設
|
||||
置<><E7BDAE><EFBFBD>影<EFBFBD><E5BDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
管<><E7AEA1><EFBFBD><EFBFBD><EFBFBD>/<2F><><EFBFBD>庫伺<E5BAAB><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/<2F><><EFBFBD>庫伺<E5BAAB><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置<EFBFBD><E7BDAE>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>解<EFBFBD><E8A7A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>http://www.varlena.com/varlena/GeneralBits/Tidb
|
||||
its/annotated_conf_e.html <20>
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html<6D>
|
||||
|
||||
硬<><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>影<EFBFBD><E5BDB1><EFBFBD><EFBFBD><EFBFBD>覽
|
||||
http://candle.pha.pa.us/main/writings/pgsql/hw_performance/inde
|
||||
x.html <20> http://www.powerpostgresql.com/PerfList/<2F>
|
||||
|
||||
3.4)PostgreSQL 裡<><E8A3A1>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼樣<E9BABC>調試<E8AABF><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>似 log_*
|
||||
<20>伺<EFBFBD><E4BCBA><EFBFBD><EFBFBD>置<EFBFBD><E7BDAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD>調試<E8AABF><E8A9A6><EFBFBD><EFBFBD><EFBFBD>測試<E6B8AC>
|
||||
<20><>幫<EFBFBD><E5B9AB><EFBFBD>
|
||||
|
||||
3.5) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC>試<EFBFBD><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Sorry, too many
|
||||
clients<74><73>已<EFBFBD>太<EFBFBD><E5A4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20>表示<E8A1A8><E7A4BA> 已<><E5B7B2><EFBFBD><EFBFBD> <20><> 100 <20>並<EFBFBD><E4B8A6>(<28><><EFBFBD>)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE>
|
||||
postgresql.conf <20>件<EFBFBD><E4BBB6><EFBFBD> max_connections <20><><EFBFBD><EFBFBD> <20><><EFBFBD> postmaster
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>併<EFBFBD><E4BDB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> postmaster<65>
|
||||
|
||||
3.6)PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容 <20><>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Bug 修<><E4BFAE>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
7.4.8 <20><><EFBFBD><EFBFBD><EFBFBD> 7.4.9 <20><><EFBFBD><EFBFBD><EFBFBD> dump <20> restore<72><65><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD>庫伺<E5BAAB><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>伺<EFBFBD><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>該<EFBFBD><E8A9B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>使<EFBFBD><E4BDBF><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB><EFBFBD>
|
||||
<20><>管<EFBFBD><E7AEA1>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>風<EFBFBD><E9A2A8><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>修<EFBFBD><E4BFAE>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> Bug
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>碼<EFBFBD><E7A2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以風<E4BBA5><E9A2A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL社<4C><E7A4BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
風<><E9A2A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
主<><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 7.3 <20><> 7.4<EFBFBD><EFBFBD><EFBFBD>常<EFBFBD>修<EFBFBD><EFBFBD>系統表<EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>dump<6D><70>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>reload<61><64><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
|
||||
3.7)(使<><E4BDBF> PostgreSQL )<29><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC> <20><>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD>人<EFBFBD>總<EFBFBD><E7B8BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>信<EFBFBD><E4BFA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC>質<EFBFBD><E8B3AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ECC RAM<41><4D>帶<EFBFBD><E5B8B6><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>SCSI
|
||||
<20><>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>質<EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>便<EFBFBD><E4BEBF>貨<EFBFBD><E8B2A8><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
PostgreSQL 幾<><E5B9BE><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>任<EFBFBD><E4BBBB>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 就<><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 究<><E7A9B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 硬<><E7A1AC><EFBFBD>置<EFBFBD><E7BDAE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
_________________________________________________________________
|
||||
|
||||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.1) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD> 幾<><E5B9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>幾<EFBFBD><E5B9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢中
|
||||
<20><><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以使<E4BBA5><E4BDBF> LIMIT <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD> ORDER BY 中
|
||||
<20><><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 幾<><E5B9BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD> <20><>使<EFBFBD><E4BDBF>游<EFBFBD><E6B8B8>(cursor)<29>FETCH<43><48><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>使<EFBFBD><E4BDBF>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT cols
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1 ;
|
||||
|
||||
4.2)
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫以<E5BAAB><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>psql裡<6C><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD>令並顯示<E9A1AF>
|
||||
<20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>psql<71><6C>使<EFBFBD><E4BDBF> \dt <20><>令<EFBFBD><E4BBA4>顯示<E9A1AF><E7A4BA><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD>解 psql 中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD>表<EFBFBD><E8A1A8>使<EFBFBD><E4BDBF> \? <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD> psql <20><><EFBFBD>代碼 <20>件
|
||||
pgsql/src/bin/psql/describe.c<><63><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> psql <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD>輸<EFBFBD><E8BCB8><EFBFBD><EFBFBD><EFBFBD> SQL
|
||||
<20><>令<EFBFBD><E4BBA4><EFBFBD> <20><><EFBFBD>以帶 -E <20><><EFBFBD> <20><> psql<71><6C> <20>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><> psql 中
|
||||
<20>給<EFBFBD><E7B5A6><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>實<EFBFBD>使<EFBFBD><E4BDBF><EFBFBD> SQL
|
||||
<20><>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容 SQL<51> INFORMATION SCHEMA <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> <20><>以<EFBFBD><E4BBA5><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以 pg_ <20><> <20>系統表<E7B5B1><E8A1A8><EFBFBD>述<EFBFBD><E8BFB0>表<EFBFBD><E8A1A8><EFBFBD>義<EFBFBD>
|
||||
|
||||
使<><E4BDBF> psql -l <20>令<EFBFBD><E4BBA4>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>以<EFBFBD>覽<EFBFBD><E8A6BD><EFBFBD><EFBFBD> pgsql/src/tutorial/syscat.source
|
||||
<20>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫系統表<E7B5B1><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>SELECT<43><54><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.3) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>8.0<EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><EFBFBD> ALTER TABLE ALTER COLUMN
|
||||
TYPE <20>
|
||||
|
||||
<20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD>
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN new_col new_data_type;
|
||||
UPDATE tab SET new_col = CAST(old_col AS new_data_type);
|
||||
ALTER TABLE tab DROP COLUMN old_col;
|
||||
COMMIT;
|
||||
|
||||
<20><> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF> VACUUM FULL tab <20>令<EFBFBD><E4BBA4>使系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA>
|
||||
|
||||
4.4) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD>大尺寸<E5B0BA><E5AFB8> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>已<EFBFBD><E5B7B2><EFBFBD><EFBFBD> 32TB <20><><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB>
|
||||
<20><><EFBFBD>表<EFBFBD><E8A1A8>大尺寸<E5B0BA><E5AFB8> 32 TB
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大尺寸<E5B0BA><E5AFB8> 1.6 TB
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大尺寸? 1 GB
|
||||
<20><><EFBFBD>表裡<E8A1A8>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>表裡<E8A1A8>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 250-1600 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>表裡<E8A1A8><E8A3A1>大索<E5A4A7><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/交<><E4BAA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8>大<EFBFBD><E5A4A7><EFBFBD>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大影<E5A4A7><E5BDB1><EFBFBD>
|
||||
|
||||
<20><>表<EFBFBD><E8A1A8>大大<E5A4A7><E5A4A7> 32 TB <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>業
|
||||
系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD>麼大<E9BABC><E5A4A7><EFBFBD><EFBFBD><EFBFBD>大表<E5A4A7><E8A1A8><EFBFBD><EFBFBD><EFBFBD> 1 GB <20><>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20><>件系統大<E7B5B1><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 32K <20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD>表大<E8A1A8><E5A4A7><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>2000<30><30>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建索<E5BBBA><E7B4A2><EFBFBD>幸<EFBFBD><E5B9B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD>MD5<44><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
並<><E4B8A6><EFBFBD><EFBFBD><EFBFBD>檢索<E6AAA2>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD>
|
||||
|
||||
4.5) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件裡<E4BBB6><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD>
|
||||
|
||||
<20><><EFBFBD> Postgres <20><><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6>身大<E8BAAB><E5A4A7>5<EFBFBD><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD>
|
||||
<20>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 100,000 <20><><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD> <20>設
|
||||
<20><><EFBFBD>串<EFBFBD>平<EFBFBD><E5B9B3><EFBFBD>度<EFBFBD><E5BAA6>20<32><30><EFBFBD><EFBFBD><EFBFBD>(Byte)<29><><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD><EFBFBD> 2.8 MB<4D><42><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD>庫<EFBFBD>件大<E4BBB6><E5A4A7><EFBFBD><EFBFBD> 5.2 MB:
|
||||
24 <20><><EFBFBD><EFBFBD>: <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
24 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
+ 4 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
----------------------------------------
|
||||
52 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD> <20>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD> 8192 <20><><EFBFBD><EFBFBD><EFBFBD> (8 KB)<29><><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
8192 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
------------------- = 158 <20><>/<2F><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
52 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
100000 <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
-------------------- = 633 <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
146 <20><>/<2F><><EFBFBD><EFBFBD>
|
||||
|
||||
633 <20><><EFBFBD><EFBFBD> * 8192 <20><><EFBFBD>/<2F> = 5,185,536 <20><><EFBFBD><EFBFBD><EFBFBD>5.2 MB<4D><42>
|
||||
|
||||
索<><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確實<E7A2BA><E5AFA6><EFBFBD>被索<E8A2AB><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD>
|
||||
|
||||
空<><E7A9BA> NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA>
|
||||
|
||||
4.6) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>
|
||||
|
||||
並<><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD> <20><><EFBFBD><EFBFBD> <20><>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>PostgreSQL
|
||||
<20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF> VACUUM ANALYZE<5A><45><EFBFBD> ANALYZE
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> 使<><E4BDBF>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD> <20><>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
統<><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
索<><E7B4A2><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ORDER BY
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大表<E5A4A7><E8A1A8><EFBFBD>次<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>快<EFBFBD><E5BFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><> LIMIT <20> ORDER BY
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起使<E8B5B7><E4BDBF><EFBFBD>話<EFBFBD><E8A9B1><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> 確信PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD> <20><>以使<E4BBA5><E4BDBF>SET
|
||||
enable_seqscan TO 'off'<27>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>次<EFBFBD><E6ACA1><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD> 就<><E5B0B1>以<EFBFBD><E4BBA5><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確實<E7A2BA><E5AFA6>快<EFBFBD><E5BFAB><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> LIKE <20> ~ <20><><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>
|
||||
* <20>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>說<EFBFBD><E8AAAA>
|
||||
+ LIKE 模<><E6A8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以 % <20><> <20>
|
||||
+ ~ <20><><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>模<EFBFBD><E6A8A1><EFBFBD><EFBFBD><EFBFBD> 以 ^ <20><> <20>
|
||||
* <20>符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD>模<EFBFBD><E6A8A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> [a-e]<5D>
|
||||
* 大<><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ILIKE <20> ~* <20><><EFBFBD>使<EFBFBD><E4BDBF>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5> 4.8
|
||||
<20><><EFBFBD>述<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
* <20><><EFBFBD> initdb <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>置 C
|
||||
locale<6C><65><EFBFBD> <20><>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> C locale <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD>麼<EFBFBD>
|
||||
<20><><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以<EFBFBD><E4BBA5>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> text_pattern_ops 索<><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
LIKE <20>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
<20><> 8.0 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD>被<EFBFBD><E8A2AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD> int2, int8 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD>
|
||||
|
||||
4.7) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3>估<EFBFBD><E4BCB0><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2>
|
||||
|
||||
<20><> EXPLAIN <20><><EFBFBD> <20>
|
||||
|
||||
4.8) <20><>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>索<EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>符 ~ <20><><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ~* <20><>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD>
|
||||
LIKE <20><>種<EFBFBD><E7A8AE><EFBFBD> ILIKE<4B>
|
||||
|
||||
大<><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常寫<E5B8B8><E5AFAB><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
|
||||
<20>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD>索<EFBFBD><E7B4A2>
|
||||
:
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>述索<E8BFB0><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA> <20><> UNIQUE <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>身<EFBFBD><E8BAAB>容<EFBFBD><E5AEB9>以<EFBFBD><E4BBA5>
|
||||
<20><>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> UNIQUE
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以使<E4BBA5><E4BDBF> CHECK <20><><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD>觸<EFBFBD><E8A7B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.9) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢裡<E8A9A2><E8A3A1><EFBFBD><EFBFBD>樣檢測<E6AAA2><E6B8AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>確<EFBFBD><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL <20><><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> IS NULL <20> IS NOT NULL 測試<E6B8AC><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ORDER BY <20><>件<EFBFBD><E4BBB6>使<EFBFBD><E4BDBF> IS NULL <20> IS NOT
|
||||
NULL 修飾符<E9A3BE><E7ACA6><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD> true <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>件<EFBFBD><E4BBB6><EFBFBD> false <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
就<><E5B0B1><EFBFBD><EFBFBD><EFBFBD> NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
|
||||
4.10) <20>種<EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>稱 說<>
|
||||
VARCHAR(n) varchar <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
符串<E7ACA6><E4B8B2><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3>義<EFBFBD><E7BEA9>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
CHAR(n) bpchar <20><><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3>義<EFBFBD><E7BEA9>度<EFBFBD><E5BAA6><EFBFBD>以空<E4BBA5> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
TEXT text <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD>
|
||||
BYTEA bytea <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF>NULL<4C>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD>
|
||||
"char" char <20><><EFBFBD><EFBFBD>符
|
||||
|
||||
<20><>系統表<E7B5B1><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>誤<EFBFBD><E8AAA4><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>稱<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD> "varlena"<22><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>說<EFBFBD><E8AAAA><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>實<EFBFBD><E5AFA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以被<E4BBA5><E8A2AB>縮<EFBFBD><E7B8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>空<EFBFBD><E7A9BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
VARCHAR(n) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大<EFBFBD><E5A4A7>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6><E4B8B2><EFBFBD>好<EFBFBD><E5A5BD> TEXT <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD>大<EFBFBD><E5A4A7><EFBFBD> 1G 左<><E5B7A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6>符串<E7ACA6>
|
||||
|
||||
CHAR(n) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度<EFBFBD><E5BAA6><EFBFBD><EFBFBD><EFBFBD>符串<E7ACA6>
|
||||
CHAR(n)<29><> <20><><EFBFBD>給<EFBFBD><E7B5A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>度以空<E4BBA5> <20><><EFBFBD>足<EFBFBD><E8B6B3><EFBFBD><EFBFBD>足<EFBFBD><E8B6B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD> <20>
|
||||
VARCHAR(n) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>給<EFBFBD><E7B5A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD> BYTEA <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>尤<EFBFBD><E5B0A4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
NULL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>差<EFBFBD><E5B7AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.11.1) <20><>樣<EFBFBD><E6A8A3>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD> SERIAL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>義<EFBFBD><E7BEA9>SERIAL<41><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
);
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5>SQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
|
||||
<20><> create_sequence <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.11.2) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> nextval() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>象裡檢索<E6AAA2><E7B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SERIAL
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>精確<E7B2BE><E7A2BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF> 4.11.1 裡<><E8A3A1><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>碼<EFBFBD>樣<EFBFBD>述<EFBFBD><E8BFB0>
|
||||
new_id = execute("SELECT nextval('person_id_seq')");
|
||||
execute("INSERT INTO person (id, name) VALUES (new_id, 'Blaise Pascal')");
|
||||
|
||||
<20>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> new_id 裡<><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> person
|
||||
表<><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 注<><E6B3A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD> SEQUENCE <20><>象<EFBFBD><E8B1A1>稱<EFBFBD><E7A8B1><EFBFBD><EFBFBD><EFBFBD>
|
||||
<table>_<serialcolumn>_seq<65><71> <20>裡 table <20> serialcolumn
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>表<EFBFBD><E8A1A8>稱<EFBFBD><E7A8B1><EFBFBD> <20> SERIAL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>稱<EFBFBD>
|
||||
|
||||
<20><>似<EFBFBD><E4BCBC><EFBFBD><EFBFBD><EFBFBD> SERIAL <20><>象<EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> currval() 檢索<E6AAA2>賦<EFBFBD><E8B3A6><EFBFBD>
|
||||
SERIAL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
execute("INSERT INTO person (name) VALUES ('Blaise Pascal')");
|
||||
new_id = execute("SELECT currval('person_id_seq')");
|
||||
|
||||
4.11.3) <20><>使<EFBFBD><E4BDBF> currval() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD>currval() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>次<EFBFBD>話<EFBFBD><E8A9B1><EFBFBD><EFBFBD><EFBFBD>賦<EFBFBD><E8B3A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.11.4) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>併<EFBFBD><E4BDB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>賦<EFBFBD><E8B3A6><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>就<EFBFBD><E5B0B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>常中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.12) <20><>麼<EFBFBD><E9BABC> OID <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC> CTID <20><>
|
||||
|
||||
PostgreSQL 裡<><E8A3A1>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OID<49><44><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建表<E5BBBA>使<EFBFBD><E4BDBF>
|
||||
WITHOUT OIDS <20><><EFBFBD> <20> OID <20><>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 4<><34><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> OID <20><><EFBFBD><EFBFBD><EFBFBD>
|
||||
PostgreSQL 伺<><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 40<34><30><EFBFBD><EFBFBD>溢<EFBFBD><E6BAA2><EFBFBD><EFBFBD> OID <20><>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系統表裡使<E8A3A1><E4BDBF> OID
|
||||
<20><>表<EFBFBD><E8A1A8><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD>繫<EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD>使<EFBFBD><E4BDBF> SERIAl <20><>代<EFBFBD><E4BBA3> OID <20> <20><> SERIAL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD><E5B0B1>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD>樣<EFBFBD><E6A8A3>溢<EFBFBD><E6BAA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>就<EFBFBD>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SERIAL8 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>8<EFBFBD><38><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
CTID <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>帶<EFBFBD><E5B8B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>移<EFBFBD><E7A7BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CTID
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD>被<EFBFBD><E8A2AB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>索<EFBFBD><E7B4A2><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
4.13) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>誤<EFBFBD><E8AAA4><EFBFBD><EFBFBD><EFBFBD>ERROR: Memory exhausted in AllocSetAlloc()<29><><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
postmaster <20><><EFBFBD>試試<E8A9A6><E8A9A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4>
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
<20>決<EFBFBD><E6B1BA><EFBFBD><EFBFBD> <20><><EFBFBD>
|
||||
shell<6C><6C><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>段<EFBFBD><E6AEB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20> <20><><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>SQL客<4C><E5AEA2>端<EFBFBD><E7ABAF> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>太<EFBFBD><E5A4AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><E5AEA2><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD><E8BFB0>令<EFBFBD>
|
||||
|
||||
4.14) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>PostgreSQL<51><4C><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> psql 裡<><E8A3A1>輸<EFBFBD><E8BCB8> SELECT version();<3B>令<EFBFBD>
|
||||
|
||||
4.15) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
使<><E4BDBF> CURRENT_TIMESTAMP<4D><50>
|
||||
CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
|
||||
4.16) <20><>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD> outer join <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
PostgreSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> SQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>裡<EFBFBD><E8A3A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
|
||||
<20><><EFBFBD>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2> t1.col <20> t2.col <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD> t1 中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t2 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><>[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>RIGHT OUTER
|
||||
JOIN<49><4E><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t2 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>FULL OUTER JOIN<49><4E><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> t1 <20> t2
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> OUTER <20><>左[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[<5B><>]<5D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>[<5B><>]<5D><><EFBFBD><EFBFBD>中
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>被稱<E8A2AB><E7A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>INNER JOIN<49><4E><EFBFBD>
|
||||
|
||||
4.17) <20><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD>詢<EFBFBD><E8A9A2>
|
||||
|
||||
<20><><EFBFBD>辦<EFBFBD><E8BEA6><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD>
|
||||
<20> <20><>PostgreSQL<51><4C><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD><EFBFBD>系統<E7B3BB><E7B5B1><EFBFBD><EFBFBD><EFBFBD>系統表<E7B5B1><E8A1A8><EFBFBD><EFBFBD><EFBFBD> <20><>
|
||||
<20>跨<EFBFBD><E8B7A8><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><> <20><><EFBFBD><EFBFBD>模<EFBFBD><E6A8A1> contrib/dblink
|
||||
<20>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>調<EFBFBD><E8AABF>實<EFBFBD><E5AFA6>跨庫<E8B7A8><E5BAAB>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD><E4BBA5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>庫<EFBFBD><E5BAAB><EFBFBD>
|
||||
<20><><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>客<EFBFBD><E5AEA2>端<EFBFBD>併<EFBFBD><E4BDB5><EFBFBD><EFBFBD>
|
||||
|
||||
4.18) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD>詳<EFBFBD><E8A9B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
http://techdocs.postgresql.org/guides/SetReturningFunctions
|
||||
|
||||
4.19) <20><><EFBFBD><EFBFBD>麼<EFBFBD><E9BABC><EFBFBD>使<EFBFBD><E4BDBF> PL/PgSQL <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>誤<EFBFBD><E8AAA4><EFBFBD><EFBFBD><EFBFBD>relation with OID
|
||||
##### does not exist<73><74><EFBFBD>
|
||||
|
||||
PL/PgSQL <20>緩<EFBFBD><E7B7A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>帶<EFBFBD><E5B8B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
PL/PgSQL
|
||||
<20><><EFBFBD><EFBFBD>訪<EFBFBD><E8A8AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>該表被<E8A1A8><E8A2AB><EFBFBD><EFBFBD>並<EFBFBD>建<EFBFBD><E5BBBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>次調<E6ACA1><E8AABF>該<EFBFBD><E8A9B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD> <20> <20><>緩<EFBFBD><E7B7A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>容<EFBFBD><E5AEB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD>解決<E8A7A3><E6B1BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> PL/PgSQL 中
|
||||
<20><>EXECUTE <20><><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD>訪<EFBFBD><E8A8AA><EFBFBD>樣<EFBFBD><E6A8A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>總<EFBFBD>被<EFBFBD><E8A2AB><EFBFBD>解<EFBFBD><E8A7A3>
|
||||
|
||||
4.20) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>寫(replication)<29><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好幾種<E5B9BE><E7A8AE>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>缺<EFBFBD><E7BCBA><EFBFBD><EFBFBD>
|
||||
|
||||
主/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD>主伺<E4B8BB><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/寫<><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>伺<EFBFBD><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><>/SELECT<43><54>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>費<EFBFBD>主/<2F><>PostgreSQL<51><4C>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
Slony-I <20>
|
||||
|
||||
<20><><EFBFBD>主伺<E4B8BB><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD>許<EFBFBD><E8A8B1><EFBFBD><EFBFBD>/寫<><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>給<EFBFBD><E7B5A6><EFBFBD><EFBFBD><EFBFBD>主<EFBFBD><E4B8BB><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>伺<EFBFBD><E4BCBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>帶<EFBFBD><E5B8B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>失<EFBFBD><E5A4B1>Pgcluster
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>種<EFBFBD><E7A8AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>好<EFBFBD><E5A5BD><EFBFBD>並<EFBFBD><E4B8A6><EFBFBD><EFBFBD><EFBFBD>以<EFBFBD>費<EFBFBD><E8B2BB><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>費<EFBFBD><E8B2BB><EFBFBD><EFBFBD><EFBFBD>硬<EFBFBD><E7A1AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>述<EFBFBD>種<EFBFBD><E7A8AE>寫模<E5AFAB><E6A8A1>
|
||||
|
||||
4.21) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD>顯示<E9A1AF>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>大寫<E5A4A7><E5AFAB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
|
||||
<20>常<EFBFBD><E5B8B8><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>( ' '
|
||||
)<29><><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>稱<EFBFBD><E7A8B1><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 大<><E5A4A7>寫<EFBFBD><E5AFAB><EFBFBD>
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>詢<EFBFBD>表<EFBFBD><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>工<EFBFBD><E5B7A5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> pgAdmin
|
||||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8>令<EFBFBD><E4BBA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||||
符<>統<EFBFBD><E7B5B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>該<EFBFBD><E8A9B2>
|
||||
* <20><><EFBFBD><EFBFBD>建表<E5BBBA><E8A1A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符使<E7ACA6><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>起<EFBFBD><E8B5B7><EFBFBD>
|
||||
* <20><><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD>寫<EFBFBD><E5AFAB><EFBFBD><EFBFBD>
|
||||
* <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>已<EFBFBD><E5B7B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>詢<EFBFBD><E8A9A2>使<EFBFBD><E4BDBF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>符<EFBFBD><E7ACA6>起<EFBFBD><E8B5B7><EFBFBD>
|
||||
849
doc/FAQ_czech
849
doc/FAQ_czech
@ -1,849 +0,0 @@
|
||||
|
||||
Frequently Asked Questions
|
||||
|
||||
Casto kladen<65> dotazy (FAQ) PostgreSQL
|
||||
|
||||
Posledn<64> aktualizace: 29. r<>jna 2007 (aktualizov<6F>no pro PostgreSQL
|
||||
8.3)
|
||||
|
||||
Soucasn<73> spr<70>vce: Bruce Momjian (bruce@momjian.us)
|
||||
|
||||
Prelozil: Pavel Stehule (pavel.stehule@gmail.com)
|
||||
|
||||
Nejaktu<74>lnejs<6A> verzi tohoto dokumentu naleznete na adrese
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ.html
|
||||
|
||||
Odpovedi na ot<6F>zky v<>zan<61> na konkr<6B>tn<74> platformy naleznete na adrese
|
||||
http://www.postgresql.org/docs/faq/.
|
||||
_________________________________________________________________
|
||||
|
||||
Obecn<63> ot<6F>zky
|
||||
|
||||
1.1) Co je to PostgreSQL? Jak<61> je spr<70>vn<76> v<>slovnost slova PostgreSQL?
|
||||
1.2) Kdo r<>d<EFBFBD> v<>voj PostgreSQL?
|
||||
1.3) Pod jakou licenc<6E> je PostgreSQL?
|
||||
1.4) Na kter<65>ch platform<72>ch lze provozovat PostgreSQL?
|
||||
1.5) Kde mohu z<>skat PostgreSQL?
|
||||
1.6) Jak<61> je posledn<64> verze?
|
||||
1.7) Kde mohu z<>skat podporu?
|
||||
1.8) Jak a kam hl<68>sit chyby?
|
||||
1.9) Kde najdu informace o zn<7A>m<EFBFBD>ch chyb<79>ch nebo nepodporovan<61>ch
|
||||
vlastnostech?
|
||||
1.10) Jak<61> je dostupn<70> dokumentace?
|
||||
1.11) Jak se mohu naucit SQL?
|
||||
1.12) Jak se mohu pripojit k t<>mu v<>voj<6F>ru?
|
||||
1.13) Jak je na tom PostgreSQL v porovn<76>n<EFBFBD> s jin<69>mi datab<61>zemi?
|
||||
1.14) Je PostgreSQL pripraven na aktu<74>ln<6C> zav<61>den<65> letn<74>ho casu v
|
||||
nekter<65>ch zem<65>ch?
|
||||
|
||||
Dotazy na klientsk<73> rozhran<61>
|
||||
|
||||
2.1) Kter<65> rozhran<61> jsou pouziteln<6C> pro PostgreSQL?
|
||||
2.2) Jak<61> n<>stroje lze pouz<75>t pro PostgreSQL a web?
|
||||
2.3) Existuje grafick<63> rozhran<61> pro PostgreSQL?
|
||||
|
||||
Administrativn<76> dotazy
|
||||
|
||||
3.1) Jak nainstalovat PostgreSQL jinam nez do /usr/local/pgsql?
|
||||
3.2) Jak nastavit pravidla pro pr<70>stup z jin<69>ch stanic?
|
||||
3.3) Jak vyladit datab<61>zi na vyss<73> v<>kon?
|
||||
3.4) Jak<61> m<>m lad<61>c<EFBFBD> prostredky?
|
||||
3.5) Co znamen<65> "Sorry, too many clients", kdyz se zkous<75>m pripojit?
|
||||
3.6) Proc je nutn<74> dump a obnoven<65> (load) datab<61>ze pri upgradu
|
||||
PostgreSQL?
|
||||
3.7) Jak<61> hardware bych mel pouz<75>vat?
|
||||
|
||||
Provozn<7A> dotazy
|
||||
|
||||
4.1) Jak z<>skat pouze prvn<76> r<>dek dotazu? N<>hodn<64> r<>dek?
|
||||
4.2) Jak z<>sk<73>m seznam tabulek, indexu, datab<61>z<EFBFBD>, a definovan<61>ch
|
||||
uzivatelu. Mohu videt dotazy, kter<65> pouz<75>v<EFBFBD> psql pro zobrazen<65> techto
|
||||
informac<61>?
|
||||
4.3) Jak zmenit datov<6F> typ sloupce?
|
||||
4.4) Jak<61> je maxim<69>ln<6C> velikost r<>dku, tabulky a datab<61>ze?
|
||||
4.5) Kolik diskov<6F>ho prostoru je potreba k ulozen<65> dat z norm<72>ln<6C>ho
|
||||
textov<6F>ho souboru?
|
||||
4.6) Muj dotaz je pomal<61> a nepouz<75>v<EFBFBD> vytvoren<65> indexy. Proc?
|
||||
4.7) Jak zjist<73>m, jak se vyhodnocuje muj dotaz?
|
||||
4.8) Jak pouz<75>t case-(in)sensitive regul<75>rn<72> v<>raz? Jak pouz<75>t index
|
||||
pro case insensitive hled<65>n<EFBFBD>?
|
||||
4.9) Jak v dotazu detekovat, ze polozka je NULL? Jak bezpecne spojit
|
||||
dva retezce, pokud mohou obsahovat NULL? Lze tr<74>dit podle toho, jestli
|
||||
je polozka NULL nebo ne?
|
||||
4.10) Jak<61> jsou rozd<7A>ly mezi ruzn<7A>mi znakov<6F>mi typy?
|
||||
4.11.1) Jak vytvorit serial/auto-increment polozku?
|
||||
4.11.2) Jak z<>skat hodnotu SERIAL po vlozen<65> r<>dku?
|
||||
4.11.3) Nezpusob<6F> currval() a nextval() probl<62>my ve v<>ce uzivatelsk<73>m
|
||||
prostred<65>?
|
||||
4.11.4) Proc nen<65> vygenerovan<61> c<>slo pouzito pri prerusen<65>
|
||||
transakce?Proc vznikaj<61> d<>ry v c<>slov<6F>n<EFBFBD> prostrednictv<74>m sekvence nebo
|
||||
typu SERIAL?
|
||||
4.12) Co to je OID? Co je to CTID?
|
||||
4.13) Co znamen<65> chybov<6F> hl<68>sen<65> "ERROR: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
4.14) Jak zjist<73>m, kterou verzi PostgreSQL pouz<75>v<EFBFBD>m?
|
||||
4.15) Jak vytvorit sloupec, kter<65> bude implicitne obsahovat aktu<74>ln<6C>
|
||||
cas?
|
||||
4.16) Jak prov<6F>st vnejs<6A> spojen<65> (outer join)?
|
||||
4.17) Jak prov<6F>st dotaz napr<70>c nekolika datab<61>zemi?
|
||||
4.18) Muze funkce vr<76>tit v<>ce r<>dku nebo sloupcu?
|
||||
4.19) Co je pr<70>cinou chyby "relation with OID xxxxx does not exist"?
|
||||
4.20) Jak<61> jsou moznosti replikace datab<61>z<EFBFBD>?
|
||||
4.21) Proc v dotazu nejsou rozpozn<7A>ny n<>zvy m<>ch tabulek nebo funkc<6B>?
|
||||
Proc jsou velk<6C> p<>smena v n<>zvech automaticky prevedena na mal<61>
|
||||
p<>smena?
|
||||
_________________________________________________________________
|
||||
|
||||
Obecn<63> ot<6F>zky
|
||||
|
||||
1.1) Co je to PostgreSQL? Jak<61> je spr<70>vn<76> v<>slovnost slova PostgreSQL?
|
||||
|
||||
V<>slovnost PostgreSQL je Post-Gres-Q-L , nebo zjednodusene Postgres .
|
||||
V rade jazyku je slovo PostgreSQL obt<62>zne vysloviteln<6C>, proto se v
|
||||
hovoru casto pouz<75>v<EFBFBD> zjednodusen<65> forma n<>zvu. Pro ty, kter<65> by si
|
||||
r<>di poslechli v<>slovnost, je k dispozici audioz<6F>znam v MP3 form<72>tu.
|
||||
|
||||
PostgreSQL je relacn<63> datab<61>ze s nekter<65>mi objektov<6F>mi rysy, kter<65> m<>
|
||||
moznosti tradicn<63>ch komercn<63>ch datab<61>zov<6F>ch syst<73>mu s nekolika
|
||||
rozs<7A>ren<65>mi, kter<65> lze naj<61>t v DBMS syst<73>mech pr<70>st<73> generace.
|
||||
Pouz<75>v<EFBFBD>n<EFBFBD> PostgreSQL nen<65> omezen<65> a vesker<65> zdrojov<6F> k<>dy jsou volne
|
||||
dostupn<70>.
|
||||
|
||||
Za v<>vojem PostgreSQL je mezin<69>rodn<64> skupina nez<65>visl<73>ch v<>voj<6F>ru
|
||||
navz<76>jem komunikuj<75>c<EFBFBD>ch prostrednictv<74>m internetu. Tento projekt nen<65>
|
||||
r<>zen z<>dnou obchodn<64> organizac<61>. Pokud se chcete pridat k projektu,
|
||||
prectete si v<>voj<6F>rsk<73> FAQ na adrese
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html .
|
||||
|
||||
1.2) Kdo r<>d<EFBFBD> v<>voj PostgreSQL?
|
||||
|
||||
Pokud budete hledat organizaci r<>d<EFBFBD>c<EFBFBD> v<>voj PostgreSQL, budete
|
||||
zklam<61>ni. Nic takov<6F>ho neexistuje. Existuj<75> pouze "core" a CVS skupiny
|
||||
uzivatelu, ale ty existuj<75> v<>ce z administr<74>torsk<73>ch duvodu nez z
|
||||
organizacn<63>ch. Projekt je smerov<6F>n komunitou v<>voj<6F>ru a uzivatelu, ke
|
||||
kter<65> se kdokoliv muze pripojit. Jedin<69> co potrebuje, je prihl<68>sit se
|
||||
do elektronick<63> konference. V<>ce ve v<>voj<6F>rsk<73>m FAQ.
|
||||
|
||||
1.3) Pod jakou licenc<6E> je PostgreSQL?
|
||||
|
||||
PostgreSQL je predmetem n<>sleduj<75>c<EFBFBD>ch autorsk<73>ch pr<70>v:
|
||||
|
||||
D<>lc<6C> Copyright (c) 1996-2009, PostgreSQL Global Development Group
|
||||
D<>lc<6C> Copyright (c) 1994-6, Regents of the University of California
|
||||
|
||||
Udeluje se opr<70>vnen<65> k uzit<69>, rozmnozov<6F>n<EFBFBD>, prov<6F>den<65> <20>prav a
|
||||
rozsirov<6F>n<EFBFBD> tohoto softwaru a dokumentace k nemu, pro jak<61>koli <20>cely,
|
||||
bez licencn<63>ho poplatku a bez p<>semn<6D> licencn<63> smlouvy, za podm<64>nky,
|
||||
ze na vsech jeho kopi<70>ch je uvedeno ozn<7A>men<65> o v<>se uveden<65>ch pr<70>vech,
|
||||
jakoz i obsah tohoto a dvou n<>sleduj<75>c<EFBFBD>ch odstavcu.
|
||||
|
||||
THE UNIVERSITY OF CALIFORNIA ("KALIFORNSK<53> UNIVERZITA") NEN<45> V Z<>DN<44>M
|
||||
PR<50>PADE ODPOVEDNA Z<>DN<44> TRET<45> OSOBE ZA PR<50>MOU, NEPR<50>MOU, ZVL<56>STN<54>,
|
||||
NAHODILOU NEBO V<>SLEDNOU SKODU, VCETNE USL<53>HO ZISKU, ZPUSOBENOU UZIT<49>M
|
||||
TOHOTO SOFTWARU A DOKUMENTACE K NEMU, A TO I V PR<50>PADE, ZE THE
|
||||
UNIVERSITY OF CALIFORNIA BYLA INFORMOV<4F>NA O MOZNOSTI VZNIKU TAKOV<4F>
|
||||
SKODY.
|
||||
|
||||
THE UNIVERSITY OF CALIFORNIA ZEJM<4A>NA NEPOSKYTUJE JAK<41>KOLI Z<>RUKY, A TO
|
||||
NEJEN Z<>RUKY OBCHODOVATELNOSTI A VHODNOSTI TOHOTO V<>ROBKU KE
|
||||
SPECIFICK<43>M <20>CELUM. N<>ZE UVEDEN<45> SOFTWARE JE POSKYTNUT "JAK STOJ<4F> A
|
||||
LEZ<45>" A THE UNIVERSITY OF CALIFORNIA NEN<45> POVINNA ZAJISTIT JEHO
|
||||
<20>DRZBU, PODPORU, AKTUALIZACI, VYLEPSEN<45> NEBO MODIFIKACI.
|
||||
|
||||
V<>se uveden<65> je BSD licence, bezn<7A> licence otevren<65>ho zdroje. Nen<65> zde
|
||||
z<>dn<64> omezen<65> ohledne uzit<69> k<>du zdroje. Jsme s t<>m spokojeni a nem<65>me
|
||||
v <20>myslu na t<>to skutecnosti cokoli menit.
|
||||
|
||||
1.4) Na kter<65>ch platform<72>ch lze provozovat PostgreSQL?
|
||||
|
||||
Strucne receno, PostgreSQL bez<65> na vsech modern<72>ch unixov<6F>ch
|
||||
syst<73>mech. Seznam tech, u kter<65>ch probehlo testov<6F>n<EFBFBD>, naleznete v
|
||||
instalacn<63>ch instrukc<6B>ch.
|
||||
|
||||
PostreSQL tak<61> bez<65> nativne na vsech Microsof Windows syst<73>mech
|
||||
odvozen<65>ch z Microsoft Windows NT jako jsou Windows 2000SP4, WindowsXP
|
||||
a Windows2003. Instalacn<63> bal<61>cek naleznete na adrese
|
||||
http://pgfoundry.org/projects/pginstaller. Na stars<72>ch syst<73>mech s
|
||||
jeste MS-DOS j<>drem lze spustit PostgreSQL s emulacn<63>m programem
|
||||
Cygwin.
|
||||
|
||||
D<>le existuje port pro Novell Netware 6 port na adrese
|
||||
http://forge.novell.com, a pro OS/2 verze (eComStation) na adrese
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
|
||||
SQL&stype=all&sort=type&dir=%2F .
|
||||
|
||||
1.5) Kde mohu z<>skat PostgreSQL?
|
||||
|
||||
Pomoc<6F> webov<6F>ho klienta z adresy http://www.postgresql.org/ftp/ nebo
|
||||
klienta ftp z adresy ftp://ftp.postgresql.org/pub/.
|
||||
|
||||
1.6) Jak<61> je posledn<64> verze?
|
||||
|
||||
Nejnovejs<6A> verz<72> PostgreSQL je verze 8.2.5
|
||||
|
||||
V pl<70>nu je uvolnovat kazdorocne jednu velkou verzi a kazd<7A>ch nekolik
|
||||
mes<65>cu mal<61> verze.
|
||||
|
||||
1.7) Kde mohu z<>skat podporu?
|
||||
|
||||
Nejcastejs<6A> forma podpory uzivatelum PostgreSQL komunitou je
|
||||
prostrednictv<74>m e-mailu. Na nasem webov<6F>m serveru naleznete odkaz na
|
||||
str<74>nky,kde se muzete prihl<68>sit do elektronick<63> konference. Pro
|
||||
zac<61>tek jsou doporucen<65> konference general nebo bugs.
|
||||
|
||||
Dals<6C> cestou je IRC kan<61>l #postgresql na Freenode (irc.freenode.net).
|
||||
K pripojen<65> pouzijte Unixov<6F> pr<70>kaz irc -x '#postgresql' "$USER"
|
||||
irc.freenode.net nebo jak<61>koholiv jin<69>ho IRC klienta. V t<>to s<>ti
|
||||
existuje jeste spanelsk<73> (#postgresql-es) a francouzsk<73>
|
||||
(#postgresqlfr) verze. Dals<6C> PostgreSQL kan<61>l naleznete na EFNet.
|
||||
|
||||
Seznam spolecnost<73> poskytuj<75>c<EFBFBD> komercn<63> podporu naleznete na adrese
|
||||
http://techdocs.postgresql.org/companies.php.
|
||||
|
||||
1.8) Jak a kam hl<68>sit chyby?
|
||||
|
||||
Vyplnte formul<75>r na adrese
|
||||
http://www.postgresql.org/support/submitbug. Na nasem ftp serveru
|
||||
ftp://ftp.postgresql.org/pub/ si overte, ze pouz<75>v<EFBFBD>te aktu<74>ln<6C> verzi
|
||||
PostreSQL.
|
||||
|
||||
Chyby reportovan<61> prostrednictv<74>m chybov<6F>ho formul<75>re nebo zasl<73>n<EFBFBD>m
|
||||
mailu do PostgreSQL konference obvykle generuje n<>sleduj<75>c<EFBFBD> odezvu:
|
||||
* Nejedn<64> se o chybu, a proc
|
||||
* Jedn<64> se o zn<7A>mou chybu, kter<65> je jiz v seznamu <20>kolu TODO
|
||||
* Tato chyba byla opravena v aktu<74>ln<6C> verzi
|
||||
* Tato chyba byla jiz opravena ve verzi, kter<65> zat<61>m nebyla
|
||||
ofici<63>lne uvolnena
|
||||
* Pozadavek na dals<6C> doplnuj<75>c<EFBFBD> informace:
|
||||
+ Operacn<63> syst<73>m
|
||||
+ Verze PostgreSQL
|
||||
+ Test reprodukuj<75>c<EFBFBD> chybu
|
||||
+ Lad<61>c<EFBFBD> informace
|
||||
+ Backtrace v<>stup debuggeru
|
||||
* Jedn<64> se o zat<61>m nezjistenou chybu, pak muzete cekat
|
||||
+ Z<>platu odstranuj<75>c<EFBFBD> chybu, kter<65> bude vlozena do dals<6C> velk<6C>
|
||||
nebo mal<61> verze
|
||||
+ Informaci, ze se jedn<64> o chybu, kterou nelze okamzite resit a
|
||||
je proto prid<69>na do TODO
|
||||
|
||||
1.9) Kde najdu informace o zn<7A>m<EFBFBD>ch chyb<79>ch nebo nepodporovan<61>ch vlastnostech?
|
||||
|
||||
PostgreSQL podporuje rozs<7A>renou podmnozinu SQL:2003. V nasem TODO
|
||||
naleznete seznam zn<7A>m<EFBFBD>ch chyb, chybej<65>c<EFBFBD>ch vlastnost<73>, a pl<70>ny do
|
||||
budoucna.
|
||||
|
||||
Odezva na pozadavek na novou vlastnost PostgreSQL je obvykle:
|
||||
* Pozadavek je jiz v TODO
|
||||
* Pozadovan<61> funkce nen<65> chten<65> protoze
|
||||
+ Duplikuje jiz existuj<75>c<EFBFBD> funkci, kter<65> respektuje SQL
|
||||
standard
|
||||
+ Implementac<61> funkce by se pr<70>lis zkomplikoval k<>d bez
|
||||
relevantn<74>ho pr<70>nosu
|
||||
+ Funkce by mohla b<>t nebezpecn<63> nebo nespolehliv<69>
|
||||
* Pozadavek je prid<69>n do TODO
|
||||
|
||||
PostgreSQL nepoz<6F>v<EFBFBD> syst<73>m pro sledov<6F>n<EFBFBD> chyb, protoze jsme zjistili,
|
||||
ze je efektivnejs<6A> pr<70>mo reagovat na maily a udrzovat aktu<74>ln<6C> TODO. V
|
||||
praxi je snaha o co nejrychlejs<6A> resen<65> chyb, a chyby, kter<65> by se
|
||||
mohly projevit u mnoha uzivatelu jsou opravov<6F>ny velice rychle. Jedin<69>
|
||||
m<>sto, kde lze dohledat vsechny zmeny, rozs<7A>ren<65> a opravy v PostgreSQL
|
||||
je CVS log. Pozn<7A>mky k verzi "Release notes" nezachycuj<75> vsechny
|
||||
zmeny, k nemz doslo.
|
||||
|
||||
1.10) Jak<61> je dostupn<70> dokumentace?
|
||||
|
||||
PostgreSQL obsahuje vynikaj<61>c<EFBFBD> dokumentaci zahrnuj<75>c<EFBFBD> manu<6E>l,
|
||||
manu<6E>lov<6F> str<74>nky a testovac<61> pr<70>klady. Pod<6F>vejte se do adres<65>re /doc.
|
||||
Manu<6E>l je pr<70>stupn<70> online na http://www.postgresql.org/docs.
|
||||
|
||||
K dispozici jsou zdarma dve online knihy na adres<65>ch
|
||||
http://www.postgresql.org/docs/books/awbook.html a
|
||||
http://www.commandprompt.com/ppbook/. Dals<6C> literaturu lze zakoupit.
|
||||
Nejpopul<75>rnejs<6A> je od Kerryho Douglase. Seznam dostupn<70> literatury je
|
||||
na http://techdocs.postgresql.org/techdocs/bookreviews.php. Jeste je
|
||||
kolekce technicky orientovan<61>ch cl<63>nku tematicky spojen<65>ch s
|
||||
PostgreSQL na adrese http://techdocs.postgresql.org/.
|
||||
|
||||
R<>dkov<6F> klient psql m<> \d pr<70>kazy pro zobrazen<65> informac<61> o typech,
|
||||
oper<65>torech, funkc<6B>ch, agregacn<63>ch funkc<6B>, atd. Pouzijte \? pro
|
||||
zobrazen<65> dostupn<70>ch pr<70>kazu.
|
||||
|
||||
Dals<6C> dokumentaci najdete na nasem webu.
|
||||
|
||||
1.11) Jak se mohu naucit SQL?
|
||||
|
||||
Pod<6F>vejte se do v<>se uveden<65> dokumentace. Dals<6C> online knihou je
|
||||
"Teach Yourself SQL in 21 Days, Second Edition" na adrese
|
||||
http://members.tripod.com/er4ebus/sql/index.htm. Mnoho nasich
|
||||
uzivatelu doporucuje knihu The Practical SQL Handbook, Bowman, Judith
|
||||
S., et al., Addison-Wesley. Dals<6C> The Complete Reference SQL, Groff et
|
||||
al., McGraw-Hill.
|
||||
|
||||
Dals<6C> online tutori<72>ly jsou dostupn<70> na adres<65>ch:
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm
|
||||
* http://sqlcourse.com
|
||||
* http://www.w3schools.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12) Jak se mohu pripojit k t<>mu v<>voj<6F>ru?
|
||||
|
||||
Prostudujte si Developer's FAQ.
|
||||
|
||||
1.13) Jak je na tom PostgreSQL v porovn<76>n<EFBFBD> s jin<69>mi datab<61>zemi?
|
||||
|
||||
Software muzeme porovn<76>vat z nekolika ruzn<7A>ch pohledu: vlastnosti,
|
||||
v<>kon, spolehlivost, podpora a cena.
|
||||
|
||||
Vlastnosti
|
||||
|
||||
PostgreSQL nab<61>z<EFBFBD> vetsinu funkc<6B> funkcionality velk<6C>ch komercn<63>ch DBMS
|
||||
syst<73>mu jako jsou: transakce, vnoren<65> dotazy, spouste, referencn<63>
|
||||
integrita a sofistikovan<61> syst<73>m zamyk<79>n<EFBFBD>. Poskytujeme urcit<69> funkce,
|
||||
kter<65> ostatn<74> syst<73>my bezne nepodporuj<75>. Napr. uzivatelem definovan<61>
|
||||
typy, dedicnost, pravidla (rules), a MVCC architekturu.
|
||||
|
||||
V<>kon
|
||||
|
||||
V<>kon PostgreSQL je srovnateln<6C> s ostatn<74>mi komercn<63>mi nebo Open
|
||||
Source datab<61>zemi. V nekter<65>ch pr<70>padech je rychlejs<6A>, jindy
|
||||
pomalejs<6A>. N<>s v<>kon je obvykle +/-10% vuci ostatn<74>m datab<61>z<EFBFBD>m.
|
||||
|
||||
Spolehlivost
|
||||
|
||||
Uvedomujeme si, ze datab<61>ze mus<75> b<>t stoprocentne spolehliv<69>, jinak je
|
||||
nepouziteln<6C>. Snaz<61>me se, aby kazd<7A> verze byla dobre otestov<6F>na a
|
||||
obsahovala minimum chyb. Kazd<7A> verze je minim<69>lne nekolik mes<65>cu v
|
||||
beta testovac<61>m rezimu. Do produkcn<63>ho rezimu se dostane, az kdyz
|
||||
nedoch<63>z<EFBFBD> k dals<6C>m zmen<65>m nebo oprav<61>m. Ver<65>me, ze jsem v<>ce nez
|
||||
srovnateln<6C> s ostatn<74>mi datab<61>zemi v t<>to oblasti.
|
||||
|
||||
Podpora
|
||||
|
||||
Na nasich internetov<6F>ch konferenc<6E>ch se setk<74>v<EFBFBD> velk<6C> skupina v<>voj<6F>ru
|
||||
a uzivatelu pri resen<65> vyskytuj<75>c<EFBFBD>ch se probl<62>mu. Nase internetov<6F>
|
||||
konference umoznuj<75> kontakt velk<6C> skupiny v<>voj<6F>ru a uzivatelu.
|
||||
Nemuzeme garantovat opravu chyby, ale komercn<63> DBMSs tak<61> vzdy
|
||||
negarantuj<75> resen<65> probl<62>mu. Ver<65>me ale, ze d<>ky pr<70>m<EFBFBD>mu kontaktu na
|
||||
v<>voj<6F>re, nasi uzivatelskou komunitu, manu<6E>lum, a dostupn<70>m zdrojov<6F>m
|
||||
k<>dum m<>me leps<70> podporu nez ostatn<74> DBMSs. Pro ty, kter<65> preferuj<75>
|
||||
komercn<63> "per-incident" podporu, existuje spolecnost<73>, kter<65> ji
|
||||
nab<61>zej<65> (FAQ sekce 1.7.)
|
||||
|
||||
Cena
|
||||
|
||||
PostgreSQL lze pouz<75>vat bezplatne (a to i pro komercn<63> pouzit<69>). Tak<61>
|
||||
muzete neomezene pouz<75>vat n<>s k<>d ve sv<73>ch produktech s v<>jimkami
|
||||
specifikovan<61>mi v nas<61> licenci (preb<65>r<EFBFBD>me BSD licenci).
|
||||
|
||||
1.14) Je PostgreSQL pripraven na aktu<74>ln<6C> zav<61>den<65> letn<74>ho casu v nekter<65>ch
|
||||
zem<65>ch?
|
||||
|
||||
Poc<6F>naje verz<72> 8.0.[4+] podporuje PostgreSQL letn<74> cas tak<61> pro USA.
|
||||
Podpora letn<74>ho casu (daylight saving time) pro Kanadu a Z<>padn<64>
|
||||
Austr<74>lii je obsazena ve verz<72>ch 8.0.[10+] a 8.1.[6+] a vsech
|
||||
n<>sleduj<75>c<EFBFBD>ch verz<72>ch. Stars<72> verze pouz<75>valy syst<73>movou datab<61>zi
|
||||
casov<6F>ch z<>n obsahuj<75>c<EFBFBD>, krome jin<69>ho, informaci o tom, zda se pro
|
||||
danou casovou z<>nu rozlisuje mezi letn<74>m a zimn<6D>m casem.
|
||||
_________________________________________________________________
|
||||
|
||||
Dotazy na klientsk<73> rozhran<61>
|
||||
|
||||
2.1) Kter<65> rozhran<61> jsou pouziteln<6C> pro PostgreSQL?
|
||||
|
||||
PostgreSQL se distribuuje pouze s rozhran<61>m pro jazyk C a embedded C.
|
||||
Vsechna dals<6C> rozhran<61> predstavuj<75> nez<65>visl<73> projekty, kter<65> je treba
|
||||
st<73>hnout z internetu samostatne. Osamostatnen<65> techto projektu
|
||||
umoznuje nez<65>vislost v<>vojov<6F>ch t<>mu a moznost vyd<79>vat nov<6F> verze bez
|
||||
ohledu na vyd<79>n<EFBFBD> nov<6F> verze PostgreSQL.
|
||||
|
||||
Nekter<65> programovac<61> jazyky jako je napr. PHP obsahuj<75> rozhran<61> pro
|
||||
PostgreSQL. Rozhran<61> pro jazyky jako je Perl, Tcl, Python a mnoho
|
||||
dals<6C>ch jsou dostupn<70> na adrese: http://gborg.postgresql.org v sekci
|
||||
Drivers/Interfaces.
|
||||
|
||||
2.2) Jak<61> n<>stroje lze pouz<75>t pro PostgreSQL a web?
|
||||
|
||||
Dobr<62>m <20>vodem do problematiky datab<61>z<EFBFBD> v prostred<65> webov<6F>ch str<74>nek
|
||||
muze b<>t web http://www.webreview.com.
|
||||
|
||||
PHP (http://www.php.net) je vynikaj<61>c<EFBFBD>m rozhran<61>m pro tvorbu webu.
|
||||
|
||||
Pro slozitejs<6A> <20>lohy se casto pouz<75>v<EFBFBD> Perl a jeho BDB:Pg rozhran<61> s
|
||||
podporou CGI - CGI.pm nebo mod_perl(u).
|
||||
|
||||
2.3) Existuje grafick<63> rozhran<61> pro PostgreSQL?
|
||||
|
||||
K dispozici je rada grafick<63>ch n<>stroju podporuj<75>c<EFBFBD>ch PostgreSQL a to
|
||||
od komercn<63>ch nebo open source v<>voj<6F>ru. Podrobn<62> seznam naleznete na
|
||||
adrese http://www.postgresql.org/docs/techdocs.54.
|
||||
_________________________________________________________________
|
||||
|
||||
Administrativn<76> dotazy
|
||||
|
||||
3.1) Jak nainstalovat PostgreSQL jinam nez do /usr/local/pgsql?
|
||||
|
||||
Pri spousten<65> configure nastavte parametr --prefix
|
||||
|
||||
3.2) Jak nastavit pravidla pro pr<70>stup z jin<69>ch stanic?
|
||||
|
||||
Ve v<>choz<6F> konfiguraci, PostgreSQL umoznuje pouze pripojen<65> z
|
||||
lok<6F>ln<6C>ho uzivatele prostrednictv<74>m Unix domain sockets nebo TCP/IP
|
||||
spojen<65>. Bez modifikace listen_addresses v souboru postgresql.conf, a
|
||||
povolen<65> adresy v souboru $PGDATA/pg_hba.conf se nelze pripojit k
|
||||
PostgreSQL z ostatn<74>ch stanic. Zmena v<>se zm<7A>nen<65>ch parametru vyzaduje
|
||||
restart datab<61>zov<6F>ho serveru.
|
||||
|
||||
3.3) Jak vyladit datab<61>zi na vyss<73> v<>kon?
|
||||
|
||||
V<>kon syst<73>mu muzete ovlivnit ve trech oblastech:
|
||||
|
||||
Zmeny dotazu
|
||||
|
||||
* Pouzit<69>m indexu vcetne c<>stecn<63>ch a funkcion<6F>ln<6C>ch
|
||||
* Pouzit<69>m COPY m<>sto opakovan<61>ch INSERTu
|
||||
* Sloucen<65>m mnoha SQL pr<70>kazu do jedn<64> transakce sn<73>zen<65>m rezie na
|
||||
commit
|
||||
* Pouz<75>v<EFBFBD>n<EFBFBD>m CLUSTERU, pokud nac<61>t<EFBFBD>te vets<74> pocet r<>dek podle indexu
|
||||
* Pouzit<69>m klauzule LIMIT v poddotazech
|
||||
* Pouzit<69>m predpripraven<65>ch dotazu
|
||||
* Pouz<75>v<EFBFBD>n<EFBFBD>m ANALYZE. Tento pr<70>kaz aktualizuje statistiky, kter<65> se
|
||||
pouz<75>vaj<61> pri optimalizaci dotazu
|
||||
* Pravideln<6C> pouzit<69> VACUUM nebo pouz<75>v<EFBFBD>n<EFBFBD> pg_autovacuum
|
||||
* Odstranen<65>m indexu pred rozs<7A>hl<68>mi zmenami v datech
|
||||
|
||||
Konfigurace serveru
|
||||
|
||||
Urcit<69> parametry v souboru postgresql.conf maj<61> vliv na v<>kon serveru.
|
||||
Detaily naleznete v pr<70>rucce Administr<74>tora v Server Run-time
|
||||
Environment/Run-time Configuration. Dals<6C> koment<6E>re naleznete v
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.ht
|
||||
ml a http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
|
||||
|
||||
V<>ber hardware
|
||||
|
||||
Vliv hardware na v<>kon serveru je pops<70>n v dokumentech
|
||||
http://candle.pha.pa.us/main/writings/pgsql/hw_performance/index.html
|
||||
a http://www.powerpostgresql.com/PerfList/.
|
||||
|
||||
3.4) Jak<61> m<>m lad<61>c<EFBFBD> prostredky?
|
||||
|
||||
Nastaven<65>m log_* promenn<6E>ch v konfiguraci serveru si vynut<75>te logov<6F>n<EFBFBD>
|
||||
dotazu a procesn<73>ch statistik, kter<65> V<>m mohou pomoci pri laden<65> a
|
||||
optimalizaci v<>konu.
|
||||
|
||||
3.5) Co znamen<65> "Sorry, too many clients", kdyz se zkous<75>m pripojit?
|
||||
|
||||
Prekrocil jste v<>choz<6F> limit, kter<65> je 100 soucasne pripojen<65>ch
|
||||
uzivatelu. V konfiguraci serveru v postgresql.conf tuto hodnotu muzete
|
||||
zvetsit zmenou hodnoty max_connection. Nezapomente restartovat server.
|
||||
|
||||
3.6) Proc je nutn<74> dump a obnoven<65> (load) datab<61>ze pri upgradu PostgreSQL?
|
||||
|
||||
Zpusob c<>slov<6F>n<EFBFBD> je pops<70>n v dokumentaci na
|
||||
http://www.postgresql.org/support/versioning. Instrukce k proveden<65>
|
||||
migrace na vyss<73> verzi jsou takt<6B>z v dokumentaci na adrese
|
||||
http://www.postgresql.org/docs/current/static/install-upgrading.html.
|
||||
|
||||
3.7) Jak<61> hardware bych mel pouz<75>vat?
|
||||
|
||||
Jelikoz PC jsou vetsinou kompatibiln<6C>, lid<69> maj<61> tendence verit, ze
|
||||
vsechna PC jsou stejne kvalitn<74>. Coz nen<65> pravda. Pameti ECC, SCSI a
|
||||
kvalitn<74> z<>kladn<64> desky jsou mnohem spolehlivejs<6A> a v<>konnejs<6A> nez
|
||||
lacinejs<6A> hardware. PostgreSQL pobez<65> na vetsine hardwaru, nicm<63>ne
|
||||
pokud je pro V<>s spolehlivost a v<>kon syst<73>mu dulezit<69>, je dobr<62>
|
||||
venovat cas nalezen<65> vhodn<64> hardwarov<6F> konfigurace. Na nasich
|
||||
elektronick<63>ch konferenc<6E>ch muzete diskutovat o vhodn<64>ch konfigurac<61>ch
|
||||
a znack<63>ch.
|
||||
_________________________________________________________________
|
||||
|
||||
Provozn<7A> dotazy
|
||||
|
||||
4.1) Jak z<>skat pouze prvn<76> r<>dek dotazu? N<>hodn<64> r<>dek?
|
||||
|
||||
Pokud potrebujete pouze nekolik r<>dku a pokud v<>te kolik, pouzijte
|
||||
SELECT LIMIT. Pokud bude mozn<7A> pouz<75>t index shoduj<75>c<EFBFBD> se s ORDER BY,
|
||||
je mozn<7A>, ze se nebude prov<6F>det cel<65> dotaz. Pokud nezn<7A>te pocet
|
||||
z<>znamu, pouzijte kurzor a pr<70>kaz FETCH.
|
||||
|
||||
Pro v<>ber n<>hodn<64>ho r<>dku pouzijte pr<70>kaz ve tvaru:
|
||||
SELECT col
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1;
|
||||
|
||||
4.2) Jak z<>sk<73>m seznam tabulek, indexu, datab<61>z<EFBFBD>, a definovan<61>ch uzivatelu.
|
||||
Mohu videt dotazy, kter<65> pouz<75>v<EFBFBD> psql pro zobrazen<65> techto informac<61>?
|
||||
|
||||
V psql pr<70>kazem \dt z<>sk<73>te seznam tabulek. <20>pln<6C> seznam pr<70>kazu psql
|
||||
z<>sk<73>te pr<70>kazem \?. Alternativne si muzete prostudovat zdrojov<6F> k<>d
|
||||
psql - soubor pgsql/src/bin/psql/describe.c, kter<65> obsahuje SQL
|
||||
pr<70>kazy, kter<65> jsou generov<6F>ny pro z<>sk<73>n<EFBFBD> v<>stupu psql "backslash"
|
||||
pr<70>kazu. Tak<61> muzete nastartovat psql s parametrem -E, kter<65> zpusob<6F>
|
||||
zobrazen<65> vsech SQL pr<70>kazu, kter<65> se odes<65>laj<61> na server. PostgreSQL
|
||||
tak<61> podporuje SQL standard INFORMACN<43> SCH<43>MATA (standardn<64> syst<73>mov<6F>
|
||||
tabulky). Klasick<63>m dotazem do syst<73>mov<6F>ch tabulek z<>sk<73>te pozadovan<61>
|
||||
informace o strukture datab<61>ze.
|
||||
|
||||
Syst<73>mov<6F> tabulky PostgreSQL (mimo r<>mec SQL standardu) pouz<75>vaj<61>
|
||||
prefix pg_. Pro zjisten<65> struktury datab<61>ze je muzete pouz<75>t tak<61>, i
|
||||
kdyz preferov<6F>ny jsou dotazy do informacn<63>ho sch<63>matu.
|
||||
|
||||
Seznam vsech datab<61>z<EFBFBD> z<>sk<73>te pr<70>kazem psql -l
|
||||
|
||||
Dals<6C> inspiraci najdete v souboru pgsql/src/tutorial/syscat.source.
|
||||
Obsahuje ilustracn<63> SELECTy potrebn<62> k z<>sk<73>n<EFBFBD> informac<61> z syst<73>mov<6F>ch
|
||||
tabulek datab<61>ze.
|
||||
|
||||
4.3) Jak zmenit datov<6F> typ sloupce?
|
||||
|
||||
Ve verz<72>ch 8.0 a pozdejs<6A>ch jednoduse:
|
||||
ALTER TABLE ALTER COLUMN TYPE
|
||||
|
||||
V stars<72>ch verz<72>ch:
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN new_col new_data_type;
|
||||
UPDATE tab SET new_col = CAST(old_col AS new_data_type);
|
||||
ALTER TABLE tab DROP COLUMN old_col;
|
||||
COMMIT;
|
||||
|
||||
Po zmene spustte pr<70>kaz VACUUM FULL, aby doslo k uvolnen<65> diskov<6F>ho
|
||||
prostoru pouzit<69>ho v tu chv<68>li jiz neplatn<74>mi z<>znamy.
|
||||
|
||||
4.4) Jak<61> je maxim<69>ln<6C> velikost r<>dku, tabulky a datab<61>ze?
|
||||
|
||||
PostgreSQL m<> tato omezen<65>:
|
||||
|
||||
Maxim<69>ln<6C> velikost datab<61>ze: neomezena (existuj<75> 32TB db)
|
||||
Maxim<69>ln<6C> velikost tabulky: 32 TB
|
||||
Maxim<69>ln<6C> velikost r<>dky: 480GB
|
||||
Maxim<69>ln<6C> velikost polozky 1 GB
|
||||
Maxim<69>ln<6C> pocet r<>dku v tabulce: neomezeno
|
||||
Maxim<69>ln<6C> pocet sloupcu v tabulce: 250-1600 podle typu
|
||||
Maxim<69>ln<6C> pocet indexu na tabulce: neomezeno
|
||||
|
||||
Ve skutecnosti nic nen<65> neomezeno, limitem b<>v<EFBFBD> vzdy dostupn<70> diskov<6F>
|
||||
pamet nebo velikost operacn<63> pameti. Pokud m<>te nekterou z techto
|
||||
hodnot neobvykle velkou, muze doj<6F>t ke sn<73>zen<65> v<>konu.
|
||||
|
||||
Maxim<69>ln<6C> velikost tabulky je 32 TB a nevyzaduje podporu velk<6C>ch
|
||||
souboru operacn<63>m syst<73>mem. Velk<6C> tabulky se ukl<6B>daj<61> do nekolika 1 GB
|
||||
souboru takze limity souborov<6F>ho syst<73>mu nejsou podstatn<74>.
|
||||
|
||||
Maxim<69>ln<6C> velikost tabulky a maxim<69>ln<6C> pocet sloupcu muzeme
|
||||
zectyrn<72>sobit nastaven<65>m velikosti bloku na 32K.
|
||||
|
||||
Indexy jsou povolen<65> pouze na sloupc<70>ch jejichz d<>lka je mens<6E> nez
|
||||
2000 znaku. Pokud tuto d<>lku prekroc<6F>me a index potrebujeme pro
|
||||
zajisten<65> jednoznacnosti, je vhodnejs<6A> pouz<75>t funkcion<6F>ln<6C> index nad
|
||||
MD5 funkc<6B> nebo fulltextov<6F> index.
|
||||
|
||||
4.5) Kolik diskov<6F>ho prostoru je potreba k ulozen<65> dat z norm<72>ln<6C>ho textov<6F>ho
|
||||
souboru?
|
||||
|
||||
PostgreSQL vyzaduje az petin<69>sobek diskov<6F>ho prostoru k ulozen<65> dat z
|
||||
textov<6F>ho souboru.
|
||||
|
||||
Napr<70>klad, uvazujme soubor se 100 tis<69>ci r<>dky obsahuj<75>c<EFBFBD> na kazd<7A>
|
||||
r<>dce cel<65> c<>slo a textov<6F> popis. Text je v prumerne dvacet bytu
|
||||
dlouh<75>. Textov<6F> soubor bude 2.8 MB dlouh<75>. Velikost datab<61>ze
|
||||
obsahuj<75>c<EFBFBD> odpov<6F>daj<61>c<EFBFBD> data bude zhruba 5.2 MB.
|
||||
24 bytu: hlavicka r<>dku (priblizne)
|
||||
24 bytu: jedna celoc<6F>seln<6C> polozka a jedna textov<6F>
|
||||
+ 4 byty: ukazatel na str<74>nku k entici
|
||||
------------------------------------------------------
|
||||
52 bytu na r<>dek
|
||||
|
||||
Velikost datov<6F> str<74>nky PostgreSQL je 8192 bytu (8KB)
|
||||
8192 bytu na str<74>nce
|
||||
---------------------- = 158 r<>dek na str<74>nku
|
||||
52 bytu za r<>dek
|
||||
|
||||
100000 r<>dek
|
||||
----------------------- = 633 str<74>nek (zaokrouhleno nahoru)
|
||||
158 r<>dek na str<74>nce
|
||||
|
||||
633 datov<6F>ch str<74>nek * 8192 bytu na kazdou str<74>nku = 5,185,536 bytu (5.2 MB)
|
||||
|
||||
Indexy nemaj<61> tak velkou rezii, ale mohou b<>t tak<61> velk<6C>, protoze
|
||||
obsahuj<75> indexovan<61> data.
|
||||
|
||||
Hodnoty NULL jsou ulozeny v bitmap<61>ch, takze zab<61>raj<61> jen velmi m<>lo
|
||||
diskov<6F>ho prostoru.
|
||||
|
||||
4.6) Muj dotaz je pomal<61> a nepouz<75>v<EFBFBD> vytvoren<65> indexy. Proc?
|
||||
|
||||
Kazd<7A> dotaz nemus<75> nutne pouz<75>t existuj<75>c<EFBFBD> indexy. Index se pouzije
|
||||
tehdy, kdyz je tabulka vets<74> nez urcit<69> minim<69>ln<6C> velikost, a dotaz
|
||||
vyb<79>r<EFBFBD> pouze procentu<74>lne malou c<>st r<>dku tabulky. To proto, ze
|
||||
n<>hodn<64> pr<70>stup k disku dan<61> cten<65>m indexu muze b<>t pomalejs<6A> nez
|
||||
line<6E>rn<72> cten<65> tabulky nebo sekvencn<63> cten<65>.
|
||||
|
||||
PostgreSQL rozhoduje o pouzit<69> indexu na z<>klade statistiky pr<70>stupu k
|
||||
tabulce. Tyto statistiky se shromazduj<75> pr<70>kazy VACUUM ANALYZE nebo
|
||||
ANALYZE. D<>ky statistik<69>m m<> optimizer informaci o poctu r<>dek v
|
||||
tabulce a muze l<>pe rozhodnout o pouzit<69> indexu. Statistiky se uplatn<74>
|
||||
pri urcen<65> optim<69>ln<6C>ho porad<61> a metody spojen<65> tabulek. Statistiky by
|
||||
se meli aktualizovat opakovane, tak jak se men<65> obsah tabulek.
|
||||
|
||||
Indexy nejsou obycejne pouzity pro setr<74>den<65> nebo spojen<65> tabulek.
|
||||
Sekvencn<63> zpracov<6F>n<EFBFBD> n<>sledovan<61> explicitn<74>m tr<74>den<65>m je obycejne
|
||||
rychlejs<6A> nez pouzit<69> indexu na velk<6C> tabulce.
|
||||
|
||||
Jinak je tomu v pr<70>pade pouzit<69> LIMIT a ORDER BY, pri kter<65>m se
|
||||
vetsinou index pouzije, jelikoz je v<>sledkem pouze mal<61> c<>st tabulky.
|
||||
|
||||
Pokud si mysl<73>te, ze optimizer mylne zvolil sekvencn<63> prohled<65>v<EFBFBD>n<EFBFBD>
|
||||
tabulky, pouzijte pr<70>kaz SET enable_seqscan TO 'off' a zkuste zda je
|
||||
prohled<65>v<EFBFBD>n<EFBFBD> s indexem rychlejs<6A>.
|
||||
|
||||
Pri vyhled<65>v<EFBFBD>n<EFBFBD> na z<>klade vzoru jako je napr. oper<65>tor LIKE nebo ~ se
|
||||
indexy pouzij<69> pouze za urcit<69>ch skutecnost<73>:
|
||||
* zac<61>tek hledan<61>ho vzoru mus<75> b<>t ukotven k zac<61>tku, tj.
|
||||
+ vzor LIKE nesm<73> zac<61>nat %
|
||||
+ ~ regul<75>rn<72> v<>raz mus<75> zac<61>nat ^
|
||||
* vzor nesm<73> zac<61>nat intervalem, napr. [a-e]
|
||||
* vyhled<65>van<61>, kter<65> nen<65> Case sensitiv jako je ILIKE nebo ~*
|
||||
nepouz<75>v<EFBFBD> indexy. Muzete ale pouz<75>t funkcion<6F>ln<6C> indexy, kter<65>
|
||||
jsou pops<70>ny v sekci 4.8
|
||||
* pri inicializaci datab<61>ze (initdb) mus<75> b<>t pouzito C locale nebo
|
||||
vytvorte speci<63>ln<6C> text_pattern_index, kter<65> umozn<7A>, pri
|
||||
respektov<6F>n<EFBFBD> zm<7A>nen<65>ch podm<64>nek pouzit<69> indexu operac<61> LIKE. Pro
|
||||
vyhled<65>v<EFBFBD>n<EFBFBD> cel<65>ch slov je mozn<7A> a v<>hodn<64> pouz<75>t fulltext.
|
||||
|
||||
4.7) Jak zjist<73>m, jak se vyhodnocuje muj dotaz?
|
||||
|
||||
Pod<6F>vejte se do n<>povedy k pr<70>kazu EXPLAIN.
|
||||
|
||||
4.8) Jak pouz<75>t case-(in)sensitive regul<75>rn<72> v<>raz? Jak pouz<75>t index pro case
|
||||
insensitive hled<65>n<EFBFBD>?
|
||||
|
||||
Vyhled<65>v<EFBFBD>n<EFBFBD> prostrednictv<74>m regul<75>rn<72>ch vzoru zajistuje oper<65>tor ~,
|
||||
kter<65> je case-sensitive. Jeho case-insensitive varianta je oper<65>tor
|
||||
~*. Case-insensitive variac<61> oper<65>toru LIKE je oper<65>tor ILIKE.
|
||||
|
||||
Case-insensitive vyhled<65>n<EFBFBD> se res<65>:
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
|
||||
Tento dotaz nepouzije standardn<64> index. Mus<75>te pouz<75>t tzv.
|
||||
funkcion<6F>ln<6C> index:
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
|
||||
Pokud index vytvor<6F>me jako unik<69>tn<74>, tak muzeme ukl<6B>dat retezce
|
||||
obsahuj<75>c<EFBFBD> mal<61> i velk<6C> p<>smena, ale nikoliv retezce, kter<65> se od sebe
|
||||
odlisuj<75> jen v mal<61>ch a velk<6C>ch p<>smenech. K zajisten<65> z<>pisu retezce
|
||||
obsahuj<75>c<EFBFBD> pouze mal<61> nebo pouze velk<6C> p<>smena pouzijte CHECK kontroly
|
||||
nebo triggery.
|
||||
|
||||
4.9) Jak v dotazu detekovat, ze polozka je NULL? Jak bezpecne spojit dva
|
||||
retezce, pokud mohou obsahovat NULL? Lze tr<74>dit podle toho, jestli je polozka
|
||||
NULL nebo ne?
|
||||
|
||||
Pokud chcete testovat hodnotu NULL pouzijte oper<65>tor IS:
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
|
||||
K spojen<65> retezcu, kter<65> mohou obsahovat hodnotu NULL, pouz<75>vejte
|
||||
funkci COALESCE(), napr.:
|
||||
SELECT COALESCE(col1, '') || COALESCE(col2, '')
|
||||
FROM tab
|
||||
|
||||
Pokud chcete tr<74>dit podle hodnoty NULL, pouzijte v<>raz IS NULL nebo IS
|
||||
NOT NULL v klauzuli ORDER. Hodnota pravda m<> prednost pred hodnotou
|
||||
false a tedy pokud pouzijete:
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
|
||||
tak z<>znamy s NULL budou na zac<61>tku setr<74>den<65>ch dat.
|
||||
|
||||
4.10) Jak<61> jsou rozd<7A>ly mezi ruzn<7A>mi znakov<6F>mi typy?
|
||||
|
||||
Typ Intern<72> n<>zev Pozn<7A>mky
|
||||
VARCHAR(n) varchar n urcuje maxim<69>ln<6C> d<>lku
|
||||
CHAR(n) bpchar retezec je do dan<61> d<>lky rozs<7A>ren mezerami
|
||||
TEXT text bez omezen<65> d<>lky
|
||||
BYTEA bytea pole bytu nespecifikovan<61> d<>lky
|
||||
"char" char jeden znak
|
||||
|
||||
Na intern<72> n<>zvy muzete narazit v syst<73>mov<6F>m katalogu nebo v nekter<65>ch
|
||||
chybov<6F>ch hl<68>sen<65>ch.
|
||||
|
||||
Ctyri prvn<76> typy jsou tzv. varlena typy (prvn<76> ctyri byty na disku
|
||||
jsou obsahuj<75> d<>lku, ostatn<74> obsahuj<75> vlastn<74> data). Skutecne obsazen<65>
|
||||
prostor je tedy o neco m<>lo vets<74> nez deklarovan<61> velikost. Na druhou
|
||||
stranu, dels<6C> retezce jsou komprimov<6F>ny, takze obsazen<65> prostor na
|
||||
disku muze b<>t mens<6E> nez se cek<65>.
|
||||
|
||||
VARCHAR(n) je vhodn<64> pro ukl<6B>d<EFBFBD>n<EFBFBD> ruzne dlouh<75>ch retezcu u kter<65>ch
|
||||
zn<7A>me d<>lkov<6F> omezen<65>, TEXT pro retezce bez omezen<65> d<>lky (maximum je
|
||||
jeden gigabyte).
|
||||
|
||||
CHAR(n) se pouz<75>v<EFBFBD> pro ulozen<65> stejne dlouh<75>ch retezcu. CHAR(n) dopln<6C>
|
||||
mezerami na specifikovanou d<>lku, VARCHAR(n) hodnoty se ukl<6B>daj<61> tak
|
||||
jak jsou. BYTEA je pro ukl<6B>d<EFBFBD>n<EFBFBD> bin<69>rn<72>ch dat - non ASCII hodnot.
|
||||
Vsechny zm<7A>nen<65> typy maj<61> podobn<62> v<>konov<6F> charakteristiky.
|
||||
|
||||
4.11.1) Jak vytvorit serial/auto-increment polozku?
|
||||
|
||||
V PostgreSQL muzete pouz<75>t datov<6F> typ SERIAL. Jeho pouzit<69>m se
|
||||
automaticky vytvor<6F> sekvence. Napr<70>klad:
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
);
|
||||
|
||||
je automaticky transformov<6F>no na:
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
|
||||
Podrobnejs<6A> informace najdete v manu<6E>lu v popisu pr<70>kazu
|
||||
create_sequence.
|
||||
|
||||
4.11.2) Jak z<>skat hodnotu SERIAL po vlozen<65> r<>dku?
|
||||
|
||||
Nejjednoduss<73>m zpusob, jak z<>skat vygenerovanou hodnotu typu SERIAL,
|
||||
je vyuz<75>t klauzuli RETURNING. Pro tabulku z 4.11.1 vypad<61> takto:
|
||||
INSERT INTO person (name) VALUES ('Blaise Pascal') RETURNING id;
|
||||
|
||||
Tak<61> muzete pouz<75>t funkci nextvall() a jej<65> v<>sledek pouz<75>t v pr<70>kazu
|
||||
INSERT, nebo zavolat currval() po proveden<65> pr<70>kazu INSERT.
|
||||
|
||||
4.11.3) Nezpusob<6F> currval() a nextval() probl<62>my ve v<>ce uzivatelsk<73>m
|
||||
prostred<65>?
|
||||
|
||||
Ne, currval vrac<61> vzdy hodnotu, kter<65> byla vygenerov<6F>na pro v<>s.
|
||||
|
||||
4.11.4) Proc nen<65> vygenerovan<61> c<>slo pouzito pri prerusen<65> transakce?Proc
|
||||
vznikaj<61> d<>ry v c<>slov<6F>n<EFBFBD> prostrednictv<74>m sekvence nebo typu SERIAL?
|
||||
|
||||
Pot<6F> co sekvence vygeneruje nov<6F> c<>slo, tak se nedoch<63>z<EFBFBD> k zamcen<65>
|
||||
sekvence a necek<65> se na <20>spesn<73> nebo ne<6E>spesn<73> dokoncen<65> transakce.
|
||||
Odvol<6F>n<EFBFBD>m transakce, kter<65> si vyz<79>dala c<>sla sekvence se tato c<>sla
|
||||
nen<65>vratne ztrat<61>.
|
||||
|
||||
4.12) Co to je OID? Co je to CTID?
|
||||
|
||||
V pr<70>pade, ze tabulku nezaloz<6F>me s atributem WITHOUT OIDS, tak m<>
|
||||
kazd<7A> r<>dek unik<69>tn<74> identifikacn<63> c<>slo OID. Toto c<>slo je 4 bajtov<6F>
|
||||
cel<65> c<>slo, kter<65> je jedinecn<63> v cel<65> instalaci. Pretece po 4
|
||||
miliard<72>ch r<>dku. PostgreSQL pouz<75>v<EFBFBD> OIDs jako intern<72> linky v
|
||||
intern<72>ch syst<73>mov<6F>ch tabulk<6C>ch.
|
||||
|
||||
K z<>sk<73>n<EFBFBD> unik<69>tn<74>ho c<>sla v nesyst<73>mov<6F>ch tabulk<6C>ch je vhodnejs<6A>
|
||||
pouzit<69> typu SERIAL nez OID, jelikoz sekvence SERIAL se pouz<75>v<EFBFBD> pouze
|
||||
pro jednu tabulku a je tud<75>z m<>ne n<>chyln<6C> na pretecen<65>. Pokud byste
|
||||
se toho ob<6F>vali, pouzijte typ SERIAL8.
|
||||
|
||||
CTID se pouz<75>v<EFBFBD> k identifikaci konkr<6B>tn<74>ho fyzick<63>ho r<>dku. CTID se
|
||||
men<65> pokud je r<>dek modifikov<6F>n nebo znovu nacten. Pouz<75>vaj<61> ho indexy
|
||||
jako adresaci fyzick<63>ch r<>dku.
|
||||
|
||||
4.13) Co znamen<65> chybov<6F> hl<68>sen<65> "ERROR: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
|
||||
Pravdepodobne jste vycerpal dostupnou virtu<74>ln<6C> pamet, nebo tvuj
|
||||
kernel m<> pr<70>lis n<>zk<7A> limity u urcit<69>ch zdroju. Pred startem
|
||||
PostgreSQL vyzkousejte:
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
Mozn<7A>, ze se projde pouze jeden pr<70>kaz - z<>lez<65> to na vasem shellu.
|
||||
Mel by zvednout limity datov<6F>ch segmentu vasich procesu na dostatecne
|
||||
velkou hodnotu a snad umoznit dokoncen<65> dotazu. Zmena limitu se bude
|
||||
aplikovat pouze na aktu<74>ln<6C> proces a na vsechny nove vytvoren<65>
|
||||
procesy. Jestlize m<>te probl<62>m s SQL klientem, protoze v<>m server
|
||||
vr<76>til pr<70>lis dat, zkuste to pred startem klienta.
|
||||
|
||||
4.14) Jak zjist<73>m, kterou verzi PostgreSQL pouz<75>v<EFBFBD>m?
|
||||
|
||||
V psql napiste:
|
||||
SELECT version();
|
||||
|
||||
4.15) Jak vytvorit sloupec, kter<65> bude implicitne obsahovat aktu<74>ln<6C> cas?
|
||||
|
||||
Pouzijte CURRENT_TIMESTAMP:
|
||||
CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
|
||||
4.16) Jak prov<6F>st vnejs<6A> spojen<65> (outer join)?
|
||||
|
||||
PostgreSQL podporuje standardn<64> SQL syntaxi pro vnejs<6A> spojen<65>. Zde
|
||||
jsou dva pr<70>klady:
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
|
||||
nebo
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
|
||||
Tyto identick<63> dotazy spoj<6F> sloupec t1.col k sloupci t2.col, a jeste
|
||||
vr<76>t<EFBFBD> vsechny nesp<73>rovan<61> r<>dky t2 (ty, kter<65> nedohled<65> v t2). RIGHT
|
||||
JOIN by pripojil vsechny nesp<73>rovan<61> r<>dky z t2. FULL JOIN vr<76>t<EFBFBD>
|
||||
vsechny sp<73>rovan<61> r<>dky i vsechny zb<7A>vaj<61>c<EFBFBD> r<>dky z obou tabulek.
|
||||
Kl<4B>cov<6F> slovo OUTER je voliteln<6C>. Bezn<7A> operace JOIN se tak<61> oznacuje
|
||||
jako vnitrn<72> spojen<65>.
|
||||
|
||||
4.17) Jak prov<6F>st dotaz napr<70>c nekolika datab<61>zemi?
|
||||
|
||||
Neexistuje z<>dn<64> zpusob, jak se v dotazu odkazovat na tabulky z jin<69>
|
||||
nez aktu<74>ln<6C> datab<61>ze. A to protoze m<> syst<73>mov<6F> tabulky ulozen<65>
|
||||
nez<65>visle v kazd<7A> datab<61>zi a nen<65> tak <20>plne zrejm<6A>, jak by se dotaz
|
||||
proveden<65> napr<70>c datab<61>zemi mel chovat.
|
||||
|
||||
Jeden z doplnku dblink umoznuje dotaz nad nekolika tabulkami pomoc<6F>
|
||||
funkc<6B>. Druh<75> zpusob je simult<6C>ln<6C> pripojen<65> klienta ke vsem
|
||||
relevantn<74>m datab<61>z<EFBFBD>m a sloucen<65> v<>sledku na strane klienta.
|
||||
|
||||
4.18) Muze funkce vr<76>tit v<>ce r<>dku nebo sloupcu?
|
||||
|
||||
Jde to jednoduse pomoc<6F> set-returning funkce. V<>ce na
|
||||
http://www.postgresql.org/docs/techdocs.17.
|
||||
|
||||
4.19) Co je pr<70>cinou chyby "relation with OID xxxxx does not exist"?
|
||||
|
||||
Nechten<65>m vedlejs<6A>m efektem kesov<6F>n<EFBFBD> SQL dotazu v PL/pgSQL funkci je
|
||||
probl<62>m s neplatn<74>mi odkazy na docasn<73> tabulky, kter<65> byly od prvn<76>ho
|
||||
spusten<65> funkce zruseny a znovu vytvoreny pred dals<6C>m spusten<65>m
|
||||
PL/pgSQL funkce. Resen<65>m je pouz<75>t pr<70>kaz EXECUTE a to proto, ze
|
||||
prov<6F>dec<65> pl<70>n SQL pr<70>kazu spousten<65>ho pr<70>kazem EXECUTE se vytv<74>r<EFBFBD>
|
||||
pokazd<7A> znovu (neukl<6B>d<EFBFBD> se do cache).
|
||||
|
||||
Tento probl<62>m by se nemel vyskytovat u PostgreSQL verze 8.3 a vyss<73>ch
|
||||
verz<72>ch.
|
||||
|
||||
4.20) Jak<61> jsou moznosti replikace datab<61>z<EFBFBD>?
|
||||
|
||||
Replikaci datab<61>ze umoznuje nekolik technoligi<67>. Kazd<7A> m<> urcit<69>
|
||||
v<>hody a nev<65>hody.
|
||||
|
||||
Master/Slave replikaci podporuje jeden hlavn<76> server, kter<65> prij<69>m<EFBFBD>
|
||||
pozadavky na z<>pis a cten<65>, a nekolik podr<64>zen<65>ch serveru, kter<65>
|
||||
umoznuj<75> pouze cten<65> (SELECT). Nejrozs<7A>renejs<6A>m volne dostupn<70>m
|
||||
resen<65>m tohoto typu je Slony-I.
|
||||
|
||||
Replikace typu Multi-master podporuje existenci nekolika serveru s
|
||||
povolen<65>m z<>pisem na v<>ce replikovan<61>ch serverech. Toto resen<65> zvysuje
|
||||
z<>tez serveru, protoze je nutn<74> synchronizace serveru.
|
||||
Nejrozs<7A>renejs<6A>m volne dostupn<70>m resen<65>m je PGCluster.
|
||||
|
||||
Jeste existuje nekolik komercn<63>ch a hardware resen<65> replikac<61>
|
||||
podporuj<75>c<EFBFBD>ch ruzn<7A> modely replikace.
|
||||
|
||||
4.21) Proc v dotazu nejsou rozpozn<7A>ny n<>zvy m<>ch tabulek nebo funkc<6B>? Proc
|
||||
jsou velk<6C> p<>smena v n<>zvech automaticky prevedena na mal<61> p<>smena?
|
||||
|
||||
Nejcastejs<6A>m duvodem nerozpozn<7A>n<EFBFBD> n<>zvu objektu bylo pouzit<69> vlozen<65>
|
||||
n<>zvu sloupce nebo tabulky mezi uvozovky pri zakl<6B>d<EFBFBD>n<EFBFBD> tabulky. Pokud
|
||||
se n<>zev zap<61>se mezi uvozovky, pak je case sensitive, a v dusledku
|
||||
toho je nutn<74> n<>zvy techto sloupcu nebo tabulek v SQL pr<70>kazech tak<61>
|
||||
vkl<6B>dat mezi uvozovky (pokud obsahuj<75> velk<6C> p<>smena). Nekter<65>
|
||||
programy, jako je napr<70>klad pgAdmin, automaticky pouz<75>vaj<61> uvozovky.
|
||||
Takze pokud chcete, aby syst<73>m identifikoval identifik<69>tor, mus<75>te:
|
||||
* nepouz<75>vat uvozovky v pr<70>kazu CREATE TABLE
|
||||
* v identifik<69>toru pouz<75>t pouze mal<61> p<>smena
|
||||
* v dotazech vkl<6B>dat identifik<69>tory do uvozovek
|
||||
1256
doc/FAQ_farsi
1256
doc/FAQ_farsi
File diff suppressed because it is too large
Load Diff
1289
doc/FAQ_french
1289
doc/FAQ_french
File diff suppressed because it is too large
Load Diff
978
doc/FAQ_german
978
doc/FAQ_german
@ -1,978 +0,0 @@
|
||||
|
||||
H<>ufig gestellte Fragen (FAQ) zu PostgreSQL
|
||||
|
||||
Current maintainer: Bruce Momjian (bruce@momjian.us).
|
||||
|
||||
Deutsche <20>bersetzung von Ian Barwick (barwick@gmail.com).
|
||||
|
||||
Letzte Aktualisierung der deutschen <20>bersetzung: Fr., den 19.10.2007,
|
||||
17:00 MEZ
|
||||
|
||||
Die aktuellste Version dieses Dokuments liegt auf der
|
||||
PostgreSQL-Website:
|
||||
* http://www.postgresql.org/docs/faqs.FAQ.html (engl.)
|
||||
* http://www.postgresql.org/docs/faqs.FAQ_german.html (dt.)
|
||||
|
||||
<20>bersetzungen dieses Dokuments in anderen Sprachen sowie plattform-
|
||||
spezifische FAQs k<>nnen unter http://www.postgresql.org/docs/faq/
|
||||
eingesehen werden.
|
||||
_________________________________________________________________
|
||||
|
||||
Allgemeine Fragen
|
||||
|
||||
1.1) Was ist PostgreSQL? Wie wird es ausgesprochen?
|
||||
1.2) Wer kontrolliert PostgreSQL?
|
||||
1.3) Welchem Copyright unterliegt PostgreSQL?
|
||||
1.4) Auf welchen Plattformen l<>uft PostgreSQL?
|
||||
1.5) Woher bekomme ich PostgreSQL?
|
||||
1.6) Was ist die neueste Version von PostgreSQL?
|
||||
1.7) Wo bekomme ich Support f<>r PostgreSQL?
|
||||
1.8) Wie kann ich einen Fehlerbericht abgeben?
|
||||
1.9) Wie erfahre ich von bekannten Bugs oder fehlenden Features?
|
||||
1.10) Welche Dokumentation ist f<>r PostgreSQL verf<72>gbar?
|
||||
1.11) Wie kann ich SQL lernen?
|
||||
1.12) Wie kann ich im Entwicklerteam mitarbeiten?
|
||||
1.13) Wie l<>uft PostgreSQL im Vergleich zu anderen Datenbanksystemen?
|
||||
1.14) Kommt PostgreSQL mit den Anpassungen der Sommerzeit in
|
||||
verschiedenen L<>ndern klar?
|
||||
|
||||
Fragen zu Benutzerprogrammen
|
||||
|
||||
2.1) Welche Schnittstellen gibt es f<>r PostgreSQL?
|
||||
2.2) Wie kann man PostgreSQL mit einer Website nutzen?
|
||||
2.3) Hat PostgreSQL eine grafische Benutzerschnittstelle?
|
||||
|
||||
Administrative Fragen
|
||||
|
||||
3.1) Wie installiere ich PostgreSQL woanders als in /usr/local/pgsql?
|
||||
3.2) Wie regle ich Zugriffe von anderen Rechnern?
|
||||
3.3) Wie kann ich eine bessere Performanz erreichen?
|
||||
3.4) Welche Debugging-Funktionen sind f<>r PostgreSQL verf<72>gbar?
|
||||
3.5) Ich bekomme die Meldung "Sorry, too many clients", wenn ich eine
|
||||
Verbindung aufzubauen versuche. Warum?
|
||||
3.6) Wie wird PostgreSQL aktualisiert?
|
||||
3.7) Welche Hardware eignet sich f<>r den Betrieb mit PostgreSQL?
|
||||
|
||||
Fragen zum Betrieb
|
||||
|
||||
4.1) Wie w<>hle ich per SELECT-Anweisung nur die ersten paar Zeilen
|
||||
bzw. eine beliebige Zeile in einer Abfrage aus?
|
||||
4.2) Wie finde ich heraus, welche Tabellen, Indexe, Datenbanken oder
|
||||
Benutzer in der Datenbank definiert sind? Wie bekomme ich die von psql
|
||||
verwendeten Abfragen?
|
||||
4.3) Wie <20>ndere ich den Datentyp einer Spalte?
|
||||
4.4) Was ist die Maximalgr<67><72>e f<>r eine Zeile, eine Tabelle, eine
|
||||
Datenbank?
|
||||
4.5) Wieviel Plattenplatz wird ben<65>tigt, um die Daten aus einer
|
||||
typischen Textdatei abzuspeichern?
|
||||
4.6) Meine Abfragen sind langsam oder benutzen die Indexe nicht.
|
||||
Warum?
|
||||
4.7) Auf welche Weise kann ich sehen, wie der Abfrage-Optimierer meine
|
||||
Abfrage auswertet?
|
||||
4.8) Wie verfahre ich bei der Suche mit regul<75>ren Ausdr<64>cken und bei
|
||||
einer Suche, bei der Gro<72>- und Kleinschreibweisen ignoriert werden?
|
||||
Wie verwende ich einen Index bei solchen Suchabfragen?
|
||||
4.9) Wie ermittle ich in einer Abfrage, ob ein Feld NULL ist?
|
||||
4.10) Was ist der Unterschied zwischen den verschiedenen CHAR-Typen?
|
||||
4.11.1) Wie erzeuge ich ein serielles Feld mit automatischer Erh<72>hung
|
||||
des Wertes?
|
||||
4.11.2) Wie bekomme ich den Wert einer SERIAL-Sequenz?
|
||||
4.11.3) F<>hrt currval() zu einer Race-Condition mit anderen Nutzern?
|
||||
4.11.4) Warum werden die Sequenzwerte nach einem Transaktionsabbruch
|
||||
nicht zur<75>ckgesetzt? Warum gibt es L<>cken in der Nummerierung meiner
|
||||
Sequenz-/SERIAL-Spalte?
|
||||
4.12) Was ist ein OID? Was ist ein CTID?
|
||||
4.13) Wieso bekomme ich den Fehler: "FATAL: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
4.14) Wie kann ich feststellen, welche PostgreSQL-Version bei mir
|
||||
l<>uft?
|
||||
4.15) Wie kann ich eine Spalte erstellen, deren Default-Wert immer die
|
||||
aktuelle Uhrzeit enthalten soll?
|
||||
4.16) Wie f<>hre ich eine OUTER JOIN durch?
|
||||
4.17) Wie kann ich Abfragen <20>ber mehrere Datenbanken hinweg ausf<73>hren?
|
||||
4.18) Wie kann ich mehrere Zeilen bzw. Spalten von einer Funktion
|
||||
zur<75>ckgeben lassen?
|
||||
4.19) Warum bekomme ich eine Fehlermeldung wie
|
||||
"relation with OID ##### does not exist" wenn ich tempor<6F>re Tabellen
|
||||
in
|
||||
PL/PgSQL-Funktionen benutze?
|
||||
4.20) Welche Replikationsl<73>sungen gibt es?
|
||||
4.21) Warum werden die Tabellen- und Spaltennamen in meiner Abfrage
|
||||
nicht erkannt? Warum werden Gro<72>buchstaben umgewandelt?
|
||||
_________________________________________________________________
|
||||
|
||||
Allgemeine Fragen
|
||||
|
||||
1.1) Was ist PostgreSQL? Wie wird es ausgesprochen?
|
||||
|
||||
Die (englische) Aussprache ist "Post-Gres-Q-L". Im allgemeinen
|
||||
Sprachgebrauch hat sich die Kurzform "Postgres" auch durchgesetzt.
|
||||
(F<>r diejenigen, die es interessiert: eine MP3-Datei mit der
|
||||
amerikanischen Aussprache befindet sich hier:
|
||||
http://www.postgresql.org/files/postgresql.mp3
|
||||
|
||||
PostgreSQL ist ein objektrelationales Datenbanksystem, das die Vorz<72>ge
|
||||
von kommerziellen Datenbanksystemen mit zukunftsweisenden Innovationen
|
||||
kombiniert. PostgreSQL ist freie Software und dessen kompletter
|
||||
Quellcode ist <20>ffentlich verf<72>gbar.
|
||||
|
||||
Die PostgreSQL-Entwicklung wird von einem Team von meist freiwilligen
|
||||
Entwicklern durchgef<65>hrt. Dieses Team ist f<>r die Gesamtentwicklung
|
||||
von PostgreSQL verantwortlich. Es handelt sich um ein
|
||||
Gemeinschaftsprojekt, das nicht von einer bestimmten Firma
|
||||
kontrolliert wird. Lesen Sie die Entwickler-FAQ:
|
||||
http://www.postgresql.org/docs/faqs.FAQ_DEV.html wenn Sie an einer
|
||||
Mitarbeit interessiert sind.
|
||||
|
||||
1.2) Wer kontrolliert PostgreSQL?
|
||||
|
||||
Falls Sie nach dem Namen eines etwaigen Inhabers bzw. nach einem
|
||||
allm<6C>chtigen Zentralkommittee suchen - sparen Sie sich die M<>he, sowas
|
||||
existiert gar nicht. Es gibt zwar das "Core Committee" sowie
|
||||
Entwickler, die CVS-Schreibberechtigung haben, jedoch haben diese
|
||||
Gruppen eher nur eine administrative Rolle. Das Projekt wird durch die
|
||||
Community gesteuert, die aus den Entwicklern sowie nat<61>rlich auch den
|
||||
Nutzern besteht - jeder kann daran teilnehmen. (Lesen Sie die
|
||||
Entwickler-FAQ: http://www.postgresql.org/docs/faqs.FAQ_DEV.html wenn
|
||||
Sie an der PostgreSQL-Entwicklung teilnehmen m<>chten).
|
||||
|
||||
1.3) Welchem Copyright unterliegt PostgreSQL?
|
||||
|
||||
PostgreSQL wird unter der klassischen BSD-Lizenz herausgegeben. Im
|
||||
Grunde genommen erlaubt diese den Nutzern, beliebig mit dem Code
|
||||
umzugehen, auch der Weiterverkauf von Bin<69>rversionen ohne Quellcode
|
||||
ist erlaubt. Die einzige Einschr<68>nkung besteht darin, dass PostgreSQL
|
||||
auf keinen Fall f<>r etwaige Probleme mit der Software haftet. Au<41>erdem
|
||||
mu<6D> der Copyright- Text in allen Kopien der Software enthalten sein.
|
||||
Dies ist der Originaltext der BSD-Lizenz:
|
||||
|
||||
PostgreSQL Data Base Management System
|
||||
|
||||
Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
|
||||
Portions Copyright (c) 1994-6 Regents of the University of California
|
||||
|
||||
Permission to use, copy, modify, and distribute this software and its
|
||||
documentation for any purpose, without fee, and without a written
|
||||
agreement is hereby granted, provided that the above copyright notice
|
||||
and this paragraph and the following two paragraphs appear in all
|
||||
copies.
|
||||
|
||||
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
|
||||
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
|
||||
INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND
|
||||
ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN
|
||||
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
|
||||
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
|
||||
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||||
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
|
||||
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
|
||||
CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
|
||||
UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
||||
|
||||
Es gilt die Copyright-Klausel im Original!
|
||||
|
||||
1.4) Auf welchen Plattformen l<>uft PostgreSQL?
|
||||
|
||||
Normalerweise kann PostgreSQL auf jeder modernen UNIX-kompatiblen
|
||||
Plattform eingesetzt werden. Diejenigen Plattformen, die bei der
|
||||
jeweiligen Versionsfreigabe getestet wurden, sind in den
|
||||
Installationsanleitungen aufgelistet.
|
||||
|
||||
PostgreSQL l<>uft auch auf Microsoft NT-basierten Betriebssystemen wie
|
||||
Windows 2000 SP4, XP und Server 2003. Ein vorgefertigtes
|
||||
Installationspaket kann von http://pgfoundry.org/projects/pginstaller
|
||||
heruntergeladen werden. DOS-basierte Windows-Versionen (Win95, Win98,
|
||||
WinMe) k<>nnen PostgreSQL nur mit Hilfe der Cygwin-Umgebung ausf<73>hren.
|
||||
|
||||
Eine Portierung f<>r Novell Netware 6 gibt es unter
|
||||
http://forge.novell.com sowie eine OS/2 (eComStation) version unter
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
|
||||
SQL&stype=all&sort=type&dir=%2F.
|
||||
|
||||
1.5) Woher bekomme ich PostgreSQL?
|
||||
|
||||
Per Web-Browser hier: http://www.postgresql.org/ftp/ und per FTP hier:
|
||||
ftp://ftp.postgresql.org/pub/.
|
||||
|
||||
1.6) Was ist die neueste Version von PostgreSQL?
|
||||
|
||||
Die neueste Version von PostgreSQL ist 8.2.5.
|
||||
|
||||
Die Freigabe einer neuen Hauptversion erfolgt in der Regel j<>hrlich,
|
||||
kleinere Korrekturversionen alle paar Monaten.
|
||||
|
||||
1.7) Wo bekomme ich Support f<>r PostgreSQL?
|
||||
|
||||
Die PostgreSQL-Community bietet Unterst<73>tzung per Mailing-Liste. Die
|
||||
Web-Seite http://www.postgresql.org/community/lists/ bietet einen
|
||||
<20>berblick. Die Listen general und bugs bieten einen guten Einstieg.
|
||||
|
||||
Eine deutschsprachige Mailing-Liste gibt es hier:
|
||||
http://archives.postgresql.org/pgsql-de-allgemein/.
|
||||
|
||||
Der wichtigsten IRC-Channel ist #postgresql auf Freenode
|
||||
(irc.freenode.net). Unter UNIX/Linux k<>nnen Sie mit z.B. irc -c
|
||||
'#postgresql' "$USER" irc.freenode.net. daran teilnehmen. Auf Freenode
|
||||
gibt es einen spanischsprachigen Channel #postgresql-es, einen
|
||||
franz<6E>sischen, #postgresqlfr sowie einen brasilianischen,
|
||||
#postgresql-br . Es gibt au<61>erdem einen PostgreSQL-Channel bei EFNet.
|
||||
|
||||
Eine Liste von Unternehmen, die Support f<>r PostgreSQL auf
|
||||
kommerzieller Basis leisten, kann unter
|
||||
http://www.postgresql.org/support/professional_support eingesehen
|
||||
werden.
|
||||
|
||||
1.8) Wie kann ich einen Fehlerbericht abgeben?
|
||||
|
||||
Nutzen Sie das Formular unter
|
||||
http://www.postgresql.org/support/submitbug. Schauen Sie aber vorher
|
||||
unter ftp://ftp.postgresql.org/pub/ nach, ob es mittlerweile eine
|
||||
neuere PostgreSQL-Version gibt, in der der Fehler behoben wurde.
|
||||
|
||||
Bugs, die <20>ber das Formular bzw. eine der Mailing-Listen
|
||||
bekanntgegeben wurden, erhalten typischerweise einer der folgenden
|
||||
Reaktionen:
|
||||
* es ist kein Bug, der Grund wird benannt
|
||||
* es ist ein bereits bekannter Bug, der bereits auf der TODO-Liste
|
||||
aufgenommen wurde
|
||||
* der Bug wurde in der aktuellen Version behoben
|
||||
* der Bug wurde bereits behoben, befindet sich aber noch nicht in
|
||||
einer offiziell ver<65>ffentlichten Version
|
||||
* es wird um eingehendere Informationen gebeten, z.B.:
|
||||
+ Betriebssystem
|
||||
+ PostgreSQL-Version
|
||||
+ reproduzierbarer Fallbeispiel
|
||||
+ Debugging-Information
|
||||
+ Debugger-Backtrace-Ausgabe
|
||||
* der Bug ist neu. Folgendes k<>nnte passieren:
|
||||
+ ein Patch wird erstellt und in der n<>chsten Version
|
||||
eingebaut;
|
||||
+ oder der Bug kann nicht sofort behoben werden und wird auf
|
||||
die TODO-Liste gesetzt
|
||||
|
||||
1.9) Wie erfahre ich von bekannten Bugs oder fehlenden Features?
|
||||
|
||||
PostgreSQL unterst<73>tzt eine erweiterte Teilmenge von SQL:2003. Siehe
|
||||
unsere TODO-Liste unter http://www.postgresql.org/docs/faqs.TODO.html
|
||||
f<>r eine Auflistung der bekannten Bugs, fehlenden Features und
|
||||
zuk<75>nftigen Pl<50>ne.
|
||||
|
||||
Eine Anfrage nach einem neuen Feature f<>hrt normalerweise zu einer der
|
||||
folgenden Antworten:
|
||||
* das Feature ist bereits auf der TODO-Liste
|
||||
* das Feature ist nicht w<>nschenswert, weil:
|
||||
+ es vorhandene Funktionalit<69>t dupliziert, welche bereits dem
|
||||
SQL-Standard folgt
|
||||
+ es w<>rde die Komplexit<69>t der Code-Basis erh<72>hen, ohne
|
||||
nennenswerte Vorteile zu bringen
|
||||
+ es w<>re unsicher bzw. unzuverl<72>ssig
|
||||
* das neue Feature wird der TODO-Liste hinzugef<65>gt
|
||||
|
||||
PostgreSQL verwendet kein Bugtracking-System, da es sich als
|
||||
effizienter erwiesen hat, E-Mails direkt zu beantworten und die
|
||||
TODO-Liste aktuell zu halten. In der Praxis werden Bugs sehr schnell
|
||||
beseitigt, und diejenigen Bugs, die Auswirkungen auf eine gro<72>e Anzahl
|
||||
von Nutzern haben, werden meist kurzfristig korrigiert. Der einzige
|
||||
<20>berblick <20>ber alle <20>nderungen, Verbesserungen und Korrekturen in
|
||||
einer PostgreSQL-Version befindet sich in den CVS-Log-Meldungen. Auch
|
||||
die Release-Notes listen nicht jede <20>nderung in der Software auf.
|
||||
|
||||
1.10) Welche Dokumentation ist f<>r PostgreSQL verf<72>gbar?
|
||||
|
||||
PostgreSQL bietet umfangreiche Dokumentation, darunter ein gro<72>es
|
||||
Handbuch, man-Pages und einige kleine Testprogramme. Siehe das /doc-
|
||||
Verzeichnis. Ausserdem sind alle Handb<64>cher online unter
|
||||
http://www.postgresql.org/docs/ verf<72>gbar.
|
||||
|
||||
Zwei B<>cher zu PostgreSQL sind online verf<72>gbar unter
|
||||
http://www.postgresql.org/docs/books/awbook.html und
|
||||
http://www.commandprompt.com/ppbook/ .
|
||||
|
||||
Eine Liste lieferbarer PostgreSQL-B<>cher befindet sich unter
|
||||
http://www.postgresql.org/docs/books Diverse technische Artikel
|
||||
befinden sich unter http://www.postgresql.org/docs/techdocs .
|
||||
|
||||
psql hat einige n<>tzliche \d-Befehle, um Informationen <20>ber Typen,
|
||||
Operatoren, Funktionen, Aggregate, usw. zu zeigen.
|
||||
|
||||
Die PostgreSQL-Website enth<74>lt noch mehr Dokumentation.
|
||||
|
||||
1.11) Wie kann ich SQL lernen?
|
||||
|
||||
Die oben erw<72>hnten PostgreSQL-spezifische B<>cher bieten einen guten
|
||||
Einstieg. Viele PostgreSQL-Anwender m<>gen "The Practical SQL Handbook"
|
||||
(Bowman et al., Addison Wesley). Andere dagegen m<>gen "The Complete
|
||||
Reference SQL" (Groff et al., McGraw-Hill).
|
||||
|
||||
Es gibt ausserdem einige n<>tzliche Online-Tutorials:
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm
|
||||
* http://sqlcourse.com
|
||||
* http://www.w3schools.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12) Wie kann ich im Entwicklerteam mitarbeiten?
|
||||
|
||||
Lesen Sie in der Entwickler-FAQ unter
|
||||
http://www.postgresql.org/docs/faqs.FAQ_DEV.html nach.
|
||||
|
||||
1.13) Wie l<>uft PostgreSQL im Vergleich zu anderen Datenbanksystemen?
|
||||
|
||||
Es gibt verschiedene Methoden, Software zu messen: Eigenschaften,
|
||||
Performanz, Zuverl<72>ssigkeit, Support und Preis.
|
||||
|
||||
Eigenschaften
|
||||
PostgreSQL besitzt die meisten Eigenschaften - wie
|
||||
Transaktionen, Unterabfragen (Subqueries), Trigger, Views,
|
||||
referenzielle Integrit<69>t bei Fremdschl<68>sseln und verfeinertes
|
||||
Locking - die bei gro<72>en kommerziellen DBMS vorhanden sind. Es
|
||||
bietet au<61>erdem einige anderen Eigenschaften, die diese nicht
|
||||
immer haben, wie benutzerbestimmte Typen, Vererbung, Regeln,
|
||||
und die Multi-Versionen-Steuerung zum Verringern
|
||||
konkurrierender Locks.
|
||||
|
||||
Performanz
|
||||
Die Performanz von PostgreSQL ist mit der von kommerziellen und
|
||||
anderen Open-Source-Datenbanken vergleichbar. In manchen
|
||||
Bereichen ist es schneller, in anderen langsamer. In der Regel
|
||||
betr<74>gt der Unterschied +/-10%.
|
||||
|
||||
Zuverl<72>ssigkeit
|
||||
Es ist selbstredend, dass ein DBMS wertlos ist, wenn es nicht
|
||||
zuverl<72>ssig arbeitet. Daher bem<65>hen wir uns, nur streng
|
||||
gepr<70>ften und best<73>ndigen Code freizugeben, der nur ein Minimum
|
||||
an Programmfehlern aufweist. Jede Freigabe hat mindestens einen
|
||||
Monat Betatest-Phase hinter sich, und unsere Freigabehistorie
|
||||
beweist, dass wir stabile und solide Versionen freigeben, die
|
||||
im Produktionsbetrieb genutzt werden k<>nnen. Wir glauben, dass
|
||||
wir im Vergleich mit anderer Datenbanksoftware vorteilhaft
|
||||
dastehen.
|
||||
|
||||
Support
|
||||
Unsere Mailinglisten bieten die M<>glichkeit, gemeinsam mit
|
||||
einer gro<72>en Gruppe von Entwicklern und Benutzern m<>gliche
|
||||
Probleme zu l<>sen. Wir k<>nnen nicht immer eine Fehlerbehebung
|
||||
garantieren, kommerzielle DBMS tun dies aber auch nicht. Der
|
||||
direkte Kontakt zur Entwickler- und Benutzergemeinschaft und
|
||||
der Zugriff auf die Handb<64>cher und den Quellcode erm<72>glicht
|
||||
einen im Vergleich zu anderen DBMS h<>herwertigeren Support. Es
|
||||
gibt jedoch auch Anbieter von kommerziellen Support-Leistungen
|
||||
(siehe FAQ-Punkt 1.7).
|
||||
|
||||
Preis
|
||||
PostgreSQL ist frei verf<72>gbar, sowohl f<>r die kommerzielle wie
|
||||
auch f<>r die nicht-kommerzielle Nutzung. Sie k<>nnen den
|
||||
PostgreSQL-Code ohne Einschr<68>nkungen (au<61>er denjenigen, die in
|
||||
der oben angegebene BSD-artigen Lizenz erw<72>hnt werden) in Ihr
|
||||
Produkt integrieren.
|
||||
|
||||
1.14) Kommt PostgreSQL mit den Anpassungen der Sommerzeit in verschiedenen
|
||||
L<>ndern klar?
|
||||
|
||||
<20>nderungen bei der US-Sommerzeit sind ab PostgreSQL Version 8.0.4
|
||||
ber<65>cksichtigt. <20>nderungen in Canada und Western Australia sind ab
|
||||
8.0.10 bzw. 8.1.6 ber<65>cksichtigt. PostgreSQL-Versionen vor 8.0 nutzen
|
||||
die Zeitzonendatenbank des Betriebssystems, um die Sommerzeit zu
|
||||
berechnen.
|
||||
|
||||
Fragen zu Benutzerprogrammen
|
||||
|
||||
2.1) Welche Schnittstellen gibt es f<>r PostgreSQL?
|
||||
|
||||
Die PostgreSQL-Installation stellt nur Schnittstellen f<>r C und
|
||||
Embedded C bereit. Alle weitere Schnittstellen sind unabh<62>ngige
|
||||
Projekte, die einzeln heruntergeladen werden werden m<>ssen. Diese
|
||||
Trennung erm<72>glicht individuelle Entwickler-Teams und
|
||||
Entwicklungszyklen f<>r die jeweiligen Projekte.
|
||||
|
||||
Einige Programmiersprachen wie PHP haben eine PostgreSQL-
|
||||
Schnittstelle bereits eingebaut. Schnittstellen f<>r Sprachen wie Perl,
|
||||
TCL, Python und viele anderen sind unter http://gborg.postgresql.org
|
||||
im Bereich Drivers/Interfaces verf<72>gbar sowie per Internet-Suche.
|
||||
|
||||
2.2) Wie kann man PostgreSQL in einer Website nutzen?
|
||||
|
||||
Eine nette Einf<6E>hrung zu datenbank-gest<73>tzten Webseiten kann unter
|
||||
http://www.webreview.com (engl.) eingesehen werden.
|
||||
|
||||
F<>r die Web-Integration ist PHP eine ausgezeichnete Schnittstelle. PHP
|
||||
gibt es bei http://www.php.net
|
||||
|
||||
F<>r komplexere Aufgaben bietet sich die Perl-Schnittstelle mit CGI.pm
|
||||
oder mod_perl.
|
||||
|
||||
2.3) Hat PostgreSQL eine grafische Benutzerschnittstelle?
|
||||
|
||||
Es gibt eine gro<72>e Anzahl von GUI-Programmen f<>r PostgreSQL - sowohl
|
||||
kommerziell als auch Open-Source. Eine ausf<73>hrliche Liste befindet
|
||||
sich unter http://www.postgresql.org/docs/techdocs.54 .
|
||||
_________________________________________________________________
|
||||
|
||||
Administrative Fragen
|
||||
|
||||
3.1) Wie installiere ich PostgreSQL woanders als in /usr/local/pgsql?
|
||||
|
||||
Bei der Ausf<73>hrung von configure die Option --prefix mit dem
|
||||
Zielverzeichnis angeben.
|
||||
|
||||
3.2) Wie regle ich Zugriffe von anderen Rechnern?
|
||||
|
||||
PostgreSQL ist standardm<64><6D>ig so eingestellt, dass Verbindungen nur vom
|
||||
lokalen Rechner <20>ber Unix Domain Sockets bzw. TCP/IP m<>glich sind.
|
||||
Verbindungen von anderen Rechnern werden erst dann erm<72>glicht, wenn
|
||||
Sie in der Datei postgresql.conf die Einstellung listen_addresses
|
||||
anpassen, in der Datei $PGDATA/pg_hba.conf host-basierte
|
||||
Authentifizierung einschalten und den Server neu starten.
|
||||
|
||||
3.3) Wie kann ich eine bessere Performanz erreichen?
|
||||
|
||||
Es gibt drei gro<72>e Bereiche, in denen Performanzverbesserungen erzielt
|
||||
werden k<>nnen:
|
||||
|
||||
Abfrageoptimierung
|
||||
Die Modifizierung von Abfragen kann eine bessere Performanz
|
||||
erzielen:
|
||||
|
||||
+ Erstellung von Indexen, einschliesslich partieller Indexe
|
||||
sowie Expressionsindexe
|
||||
+ Einsatz von COPY anstelle multipler INSERT-Anweisungen
|
||||
+ Gruppierung von mehreren Abfragen innerhalb einer
|
||||
Transaktion, um Aufwand beim Abschluss von Transaktionen
|
||||
einzusparen
|
||||
+ Einsatz von CLUSTER beim Holen von einer gro<72>en Anzahl von
|
||||
Datenreihen aus einem Index
|
||||
+ Einsatz von LIMIT, um eine Untermenge der Abfragen-
|
||||
ergebnisse zur<75>ckzuliefern
|
||||
+ Einsatz von vorbereiteten Befehlen (prepared queries)
|
||||
+ Einsatz von ANALYZE, um die Datenbankstatistik f<>r den
|
||||
Abfragenplaner aktuell zu halten
|
||||
+ Regelm<6C><6D>iger Einsatz von VACUUM bzw. pg_autovacuum
|
||||
+ Bei gro<72>en Datenver<65>nderungen die L<>schung von Indexen
|
||||
|
||||
Server-Konfiguration
|
||||
Einige Einstellungen in der Datei postgresql.conf wirken auf
|
||||
die Performanz aus. Das Handbuch enth<74>lt unter
|
||||
http://www.postgresql.org/docs/current/static/runtime-config.ht
|
||||
ml eine komplette Auflistung. Kommentare zu den jeweiligen
|
||||
Einstellungen gibt es unter
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_co
|
||||
nf_e.html und
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
|
||||
|
||||
Hardware-Auswahl
|
||||
Die Auswirkung von Hardware auf Performanz wird unter
|
||||
http://momjian.us/main/writings/pgsql/hw_performance/index.html
|
||||
und http://www.powerpostgresql.com/PerfList/ erl<72>utert.
|
||||
|
||||
3.4) Welche Debugging-Funktionen sind f<>r PostgreSQL verf<72>gbar?
|
||||
|
||||
Unter den Optionen f<>r die Server-Konfigurierung gibt es zahlreiche
|
||||
log_*-Variablen, die die Ausgabe von Abfrage- und Prozessstatistiken
|
||||
erm<72>glichen. Diese k<>nnen f<>r Debugging-Zwecke sowie Performanz-Tests
|
||||
sehr n<>tzlich sein.
|
||||
|
||||
3.5) Ich bekomme die Meldung "Sorry, too many clients", wenn ich eine
|
||||
Verbindung aufzubauen versuche. Warum?
|
||||
|
||||
Ihr System hat die maximal zul<75>ssige Anzahl von Datenbankverbindungen
|
||||
erreicht (Voreinstellung 100). Sie m<>ssen die maximale Anzahl der
|
||||
gleichzeitig ausf<73>hrbaren Backend-Prozesse hochsetzen, indem Sie in
|
||||
postgresql.conf den Wert max_connections <20>ndern und den Server
|
||||
neustarten.
|
||||
|
||||
3.6) Wie wird PostgreSQL aktualisiert?
|
||||
|
||||
Allgemeine Informationen zur Aktualisierung von PostgreSQL gibt es auf
|
||||
der Seite http://www.postgresql.org/support/versioning. Detaillierte
|
||||
technische Informationen gibt es auf der Seite
|
||||
http://www.postgresql.org/docs/current/static/install-upgrading.html
|
||||
|
||||
3.7) Welche Hardware eignet sich f<>r den Betrieb mit PostgreSQL?
|
||||
|
||||
PostgreSQL l<>uft auf fast jeder Hardware-Kombination. Im PC-Bereich
|
||||
gibt es allerdings sehr gro<72>e Abweichungen in der Qualit<69>t. F<>r einen
|
||||
Arbeitsplatz- oder Entwicklungsrechner mag dies nicht so bedeutend
|
||||
sein, im Server-Betrieb jedoch lohnt sich auf jeden Fall die
|
||||
Investition in teurere Bestandteile (Stichw<68>rter ECC-Speicher, SCSI,
|
||||
Hauptplatinen und Netzteile von namhaften Herstellern). Nutzen Sie
|
||||
unsere Mailing-Listen, um Hardware-Optionen zu diskutieren.
|
||||
_________________________________________________________________
|
||||
|
||||
Fragen zum Betrieb
|
||||
|
||||
4.1) Wie w<>hle ich per SELECT-Anweisung nur die ersten paar Zeilen bzw. eine
|
||||
beliebige Zeile in einer Abfrage aus?
|
||||
|
||||
Wenn Sie bei der Ausf<73>hrung der Abfrage die Anzahl der anzufordenden
|
||||
Reihen bereits kennen, nutzen Sie LIMIT. Wenn die ORDER BY- Anweisung
|
||||
mit einem Index verwendet wird, ist es m<>glich, dass die gesamte
|
||||
Abfrage nicht ausgef<65>hrt werden muss. Wenn Sie die Anzahl der der
|
||||
anzufordenden Reihen nicht kennen, verwenden Sie einen Cursor und
|
||||
FETCH.
|
||||
|
||||
Um eine beliebige Zeile auszuw<75>hlen, nutzen Sie ORDER BY random():
|
||||
SELECT spalte
|
||||
FROM tabelle
|
||||
ORDER BY random()
|
||||
LIMIT 1
|
||||
|
||||
|
||||
4.2) Wie finde ich heraus, welche Tabellen, Indexe, Datenbanken oder Benutzer
|
||||
in der Datenbank definiert sind? Wie bekomme ich die von psql verwendeten
|
||||
Abfragen?
|
||||
|
||||
In psql zeigt der Befehl \dt eine Liste der Datenbanktabellen. Weitere
|
||||
psql-Befehle lassen sich mit \? anzeigen. Sie k<>nnen sich die Datei
|
||||
pgsql/src/bin/psql/describe.c mit dem Quellcode f<>r psql ansehen. Sie
|
||||
enth<74>lt die SQL-Abfragen, die die Backslash-Kommandos (\) ausf<73>hren.
|
||||
Sie k<>nnen psql auch mit der -E Option starten. Danach gibt psql die
|
||||
Abfragen aus, die es bei der Ausf<73>hrung der Befehle benutzt. Au<41>erdem
|
||||
biete PostgreSQL ein SQL-kompatibles INFORMATION SCHEMA, das
|
||||
Metainformation <20>ber die Datenbank zur Verf<72>gung stellt.
|
||||
|
||||
Mit psql -l k<>nnen Sie alle Datenbanken anzeigen lassen.
|
||||
|
||||
Die Datei pgsql/src/tutorial/syscat.source enth<74>lt au<61>erdem viele
|
||||
SELECT- Abfragen, mit deren Hilfe man Information <20>ber die
|
||||
Systemtabellen erhalten kann.
|
||||
|
||||
4.3) Wie <20>ndere ich den Datentyp einer Spalte?
|
||||
|
||||
Ab Version 8.0 kann der Datentyp einer Spalte mit ALTER TABLE ALTER
|
||||
COLUMN TYPE ge<67>ndert werden, sofern der neue Datentyp die Werte des
|
||||
alten Datentype aufnehmen kann.
|
||||
|
||||
Bei fr<66>heren Versionen gehen Sie wie folgt vor:
|
||||
BEGIN;
|
||||
ALTER TABLE tabelle ADD COLUMN neue_spalte neuer_datentyp;
|
||||
UPDATE tabelle SET neue_spalte = CAST(alte_spalte AS neuer_datentyp);
|
||||
ALTER TABLE tabelle DROP COLUMN alte_spalte;
|
||||
COMMIT;
|
||||
|
||||
|
||||
Um den Speicherplatz freizugeben, der von der gel<65>schten Spalte
|
||||
verwendet wurde, f<>hren Sie VACUUM FULL aus.
|
||||
|
||||
4.4) Was ist die Maximalgr<67><72>e f<>r eine Zeile, eine Tabelle, eine Datenbank?
|
||||
|
||||
Es bestehen folgende Obergrenzen:
|
||||
Maximale Gr<47><72>e eine Datenbank? unbeschr<68>nkt (es existieren
|
||||
Datenbanken mit 32 TB)
|
||||
Maximale Gr<47><72>e einer Tabelle? 32 TB
|
||||
Maximale Gr<47><72>e einer Zeile? 400 GB
|
||||
Maximale Gr<47><72>e einer Spalte? 1 GB
|
||||
Maximale Anzahl von Zeilen in einer Tabelle?
|
||||
unbeschr<68>nkt
|
||||
Maximale Anzahl von Spalten in einer Tabelle?
|
||||
250-1600 je nach Spaltentyp
|
||||
Maximale Anzahl von Indexen f<>r eine Tabelle?
|
||||
unbeschr<68>nkt
|
||||
|
||||
Selbstverst<73>ndlich sind dies theoretische Werte, die oft durch die
|
||||
verf<72>gbaren Platten- und Speicherressourcen beschr<68>nkt werden. Extreme
|
||||
Gr<47><72>en k<>nnen zu Leistungseinbu<62>en f<>hren.
|
||||
|
||||
Die maximale Tabellengr<67><72>e von 32 TB ben<65>tigt keine
|
||||
Large-File-Unterst<73>tzung im Betriebssystem. Gro<72>e Tabellen werden in
|
||||
Dateien mit einer Gr<47><72>e von je 1 GB aufgeteilt, wodurch etwaige
|
||||
dateisystem-bedingte Beschr<68>nkungen nicht relevant sind.
|
||||
|
||||
Die maximale Tabellengr<67><72>e und die maximale Anzahl von Spalten k<>nnen
|
||||
vervierfacht werden, indem man die Default-Blockgr<67><72>e auf 32 KB
|
||||
heraufsetzt. Die Tabellengr<67><72>e kann auch durch Tabellenpartitionierung
|
||||
vergr<67><72>ert werden.
|
||||
|
||||
Eine Einschr<68>nkung ist, dass Indexe nur auf Spalten erstellt werden
|
||||
k<>nnen, die bis etwa 2.000 Zeichen gro<72> sind. Um auf gr<67><72>ere Spalten
|
||||
eine UNIQUE-Constraint setzen zu k<>nnen, nutzen Sie einen funktionalen
|
||||
Index mit dem MD5-Hash-Wert der Spalte. Um innerhalb einer gro<72>en, mit
|
||||
Text belegten Spalte suchen zu k<>nnen, verwenden Sie einen
|
||||
Volltext-Index.
|
||||
|
||||
4.5) Wieviel Plattenplatz wird ben<65>tigt, um die Daten aus einer typischen
|
||||
Textdatei abzuspeichern?
|
||||
|
||||
Eine PostgreSQL-Datenbank kann beim Abspeichern einer einfachen
|
||||
Textdatei bis zu f<>nfmal mehr Platz gegen<65>ber der eigentlichen Gr<47><72>e
|
||||
der Datei beanspruchen.
|
||||
|
||||
Betrachten wir eine Datei mit 100.000 Zeilen mit einem Integer und
|
||||
einer Textbeschreibung pro Zeile. Gehen wir davon aus, dass die
|
||||
durchschnittliche L<>nge der Textbeschreibung 20 Byte betr<74>gt. Die
|
||||
einfache Datei w<>rde 2,8 MB gro<72> sein. Die Gr<47><72>e der
|
||||
PostgreSQL-Datenbankdatei, die diese Daten enth<74>lt, liegt ungef<65>hr bei
|
||||
5,2 MB:
|
||||
24 Bytes: jeder Zeilenkopf (ungef<65>hr)
|
||||
+24 Bytes: ein Integer-Feld und ein Textfeld
|
||||
+ 4 Bytes: Zeiger auf der Datenseite auf den Tupel
|
||||
-----------------------------------------------
|
||||
52 Bytes pro Zeile
|
||||
|
||||
Die Gr<47><72>e einer Datenseite in PostgreSQL betr<74>gt 8192 Bytes (8 KB),
|
||||
also:
|
||||
8192 Bytes pro Seite
|
||||
--------------------- = 146 Zeilen pro Seite (abgerundet)
|
||||
52 Bytes pro Zeile
|
||||
|
||||
100.000 Datenzeilen
|
||||
------------------------ = 685 Datenbankseiten (aufgerundet)
|
||||
158 Zeilen pro Seite
|
||||
|
||||
633 Datenbankseiten * 8192 Bytes pro Seite = 5,185,536 bytes (5,2 MB)
|
||||
|
||||
Indexe beanspruchen nicht so viel Platz. Da sie jedoch die Daten
|
||||
beinhalten, die sie indizieren, k<>nnen auch sie sehr gro<72> werden.
|
||||
|
||||
NULL-Werte werden als Bitmaps gespeichert, wodurch sie sehr wenig
|
||||
Platz in Anspruch nehmen.
|
||||
|
||||
4.6) Meine Abfragen sind langsam oder benutzen die Indexe nicht. Warum?
|
||||
|
||||
Indexe werden nicht automatisch bei jeder Abfrage verwendet. Indexe
|
||||
werden nur dann verwendet, wenn die abzufragende Tabelle eine
|
||||
bestimmte Gr<47><72>e <20>bersteigt, und die Abfrage nur eine kleine
|
||||
Prozentzahl der Tabellenzeilen abfragt. Der Grund hierf<72>r ist der,
|
||||
dass die durch einen Index verursachten Festplattenzugriffe manchmal
|
||||
l<>nger dauern w<>rden als ein einfaches Auslesen aller Tabellenzeilen
|
||||
(sequentieller Scan).
|
||||
|
||||
Um festzustellen, ob ein Index verwendet werden soll, braucht
|
||||
PostgreSQL Statistiken <20>ber die Tabelle. Diese Statistiken werden
|
||||
durch die Anweisungen VACUUM ANALYZE bzw. ANALYZE berechnet. Anhand
|
||||
der Statistiken kennt der Abfragenoptimierer die Anzahl der
|
||||
Tabellenzeilen und kann besser entscheiden, ob Indexe verwendet werden
|
||||
sollen. Statistiken sind auch bei der Ermittlung der optimalen
|
||||
JOIN-Reihenfolgen und -Methoden wertvoll. Daher sollten diese
|
||||
regelm<6C>ssig durchgef<65>hrt werden, da sich der Inhalt einer Tabelle ja
|
||||
auch ver<65>ndert.
|
||||
|
||||
Indexe werden normalerweise nicht in ORDER BY-Abfrage oder in JOINs
|
||||
verwendet. Ein sequentieller Scan mit anschlie<69>endem explizitem
|
||||
Sortiervorgang ist normalerweise schneller als ein Index-Scan einer
|
||||
gro<72>en Tabelle. Jedoch wird bei einer Abfrage, in der LIMIT zusammen
|
||||
mit ORDER BY verwendet wird, oftmals ein Index verwendet, da nur ein
|
||||
kleiner Abschnitt der Tabelle zur<75>ckgeliefert wird.
|
||||
|
||||
Sollte es danach aussehen, also ob der Optimierer irrt<72>mlich einen
|
||||
sequentiellen Scan ausf<73>hrt, f<>hren Sie SET enable_seqscan TO 'off'
|
||||
aus und pr<70>fen Sie, ob die Indexabfrage dadurch scheller geworden ist.
|
||||
|
||||
Bei der Nutzung von Wildcard-Operatoren wie LIKE oder ~, k<>nnen Indexe
|
||||
nur unter bestimmten Umst<73>nden verwendet werden:
|
||||
* Das Suchmuster muss sich an Anfang des Strings befinden, d.h.:
|
||||
+ LIKE-Suchmuster d<>rfen nicht mit % anfangen;
|
||||
+ ~ (regul<75>re Ausdr<64>cke) m<>ssen mit ^ anfangen.
|
||||
* Das Suchmuster darf nicht mit einer Zeichenklasse (z.B. [a-e])
|
||||
beginnen.
|
||||
* Suchmuster, die Gross- und Kleinschreibung nicht ber<65>cksichtigen
|
||||
(z.B. ILIKE bzw. ~*), verwenden keine Indexe. Stattdessen k<>nnen
|
||||
funktionale Indexe verwendet werden, die im Punkt 4.8 beschrieben
|
||||
werden.
|
||||
* Die Standard-Locale "C" muss w<>hrend der Datenbank-Initialisierung
|
||||
mit initdb verwendet worden sein, da andere locales den
|
||||
n<>chstgr<67><72>ten Wert nicht ermitteln k<>nnen. Es ist allerdings
|
||||
m<>glich, einen besonderen text_pattern_ops-Index f<>r solche F<>lle
|
||||
zu erstellen.
|
||||
|
||||
In Versionen vor 8.0 werden Indexe oft nicht benutzt, wenn die
|
||||
jeweiligen Datentypen nicht genau <20>bereinstimmen. Dies gilt besonders
|
||||
f<>r Indexe auf Spalten mit den Datentypen INT2, INT8 und NUMERIC
|
||||
|
||||
4.7) Auf welche Weise kann ich sehen, wie der Abfrage-Optimierer meine
|
||||
Abfrage auswertet?
|
||||
|
||||
Vgl. die EXPLAIN Man-Page.
|
||||
|
||||
4.8) Wie verfahre ich bei der Suche mit regul<75>ren Ausdr<64>cken und bei einer
|
||||
Suche, bei der Gro<72>- und Kleinschreibweisen ignoriert werden? Wie verwende
|
||||
ich einen Index bei solchen Suchabfragen?
|
||||
|
||||
Der Operator ~ wendet einen regul<75>ren Ausdruck an und ~* wendet ihn
|
||||
an, ohne die Gro<72>- und Kleinschreibung zu beachten. Ebenso beachtet
|
||||
LIKE die Gro<72>- und Kleinschreibung, und ILIKE nicht.
|
||||
|
||||
Gleichheitsvergleiche, die Gro<72>- und Kleinschreibung ignorieren,
|
||||
werden in der Regel so ausgedruckt:
|
||||
SELECT *
|
||||
FROM tabelle
|
||||
WHERE LOWER(spalte) = 'abc'
|
||||
|
||||
Hier wird kein normaler Index benutzt. Legt man hingegen einen
|
||||
funktionalen Index an, so wird er auf jeden Fall verwendet:
|
||||
CREATE INDEX tabelle_index ON tabelle (LOWER(spalte))
|
||||
|
||||
Falls der obige Index als einen UNIQUE-Index angelegt wird, k<>nnen
|
||||
keine Werte in die Spalte eingef<65>gt werden, die sich nur durch ihre
|
||||
Gro<72>- und Kleinschreibung unterscheiden. Um Fehler zu vermeiden mu<6D>
|
||||
ein CHECK-Constraint oder ein Trigger eingesetzt werden.
|
||||
|
||||
4.9) Wie ermittle ich in einer Abfrage, ob ein Feld NULL ist? Kann nach der
|
||||
NULL-Belegung sortiert werden?
|
||||
|
||||
Testen Sie die Spalte mit IS NULL bzw. IS NOT NULL.
|
||||
SELECT *
|
||||
FROM tabelle
|
||||
WHERE spalte IS NULL
|
||||
|
||||
Um die Spalte danach zu sortieren, ob sie mit NULL belegt ist oder
|
||||
nicht, verwenden Sie die Bedingungen IS NULL bzw. IS NOT NULL in der
|
||||
ORDER BY-Klausel. Da Bedingungen, die wahr sind, h<>her als das
|
||||
Gegenteil sortiert werden, bewirkt die folgende Abfrage, dass die
|
||||
NULL-Spalten zuerst gelistet werden:
|
||||
SELECT *
|
||||
FROM tabelle
|
||||
ORDER BY (spalte IS NOT NULL)
|
||||
|
||||
4.10) Was ist der Unterschied zwischen den verschiedenen CHAR-Typen?
|
||||
|
||||
Typ interner Name Bemerkungen
|
||||
-------------------------------------------------
|
||||
VARCHAR(n) varchar die Gr<47><72>e legt die Maximall<6C>nge fest; kein
|
||||
Auff<66>llen mit Leerzeichen
|
||||
CHAR(n) bpchar mit Leerzeichen gef<65>llt bis zur angegebenen L<>nge
|
||||
TEXT text keine obere Schranke f<>r die L<>nge
|
||||
BYTEA bytea Bytearray mit variabler L<>nge (auch f<>r
|
||||
'\0'-Bytes geeignet)
|
||||
"char" char 1 Zeichen
|
||||
|
||||
Der interne Name kommt vor allem in den Systemkatalogen und in manchen
|
||||
Fehlermeldungen vor.
|
||||
|
||||
Die ersten vier Typen sind "varlena"-Typen (d.h. die ersten vier Bytes
|
||||
geben die L<>nge an, gefolgt von den Daten). Daher ist der tats<74>chlich
|
||||
belegte Platz immer etwas mehr als die deklarierte Feldgr<67><72>e.
|
||||
Allerdings wird unter Umst<73>nden auf diese Datentypen Datenkompression
|
||||
durch das TOAST- Verfahren angewendet, womit der tats<74>chlich belegte
|
||||
Platz auch geringer als erwartet ausfallen kann.
|
||||
|
||||
F<>r die Speicherung von Zeichenketten variabler L<>nge empfiehlt sich
|
||||
VARCHAR(n). Die maximale L<>nge eines VARCHAR(n)-Felds wird bei der
|
||||
Tabellendefinition festgelegt. TEXT setzt keine L<>ngengrenze,
|
||||
allerdings gibt es eine systembedingte Obergrenze von 1 GB.
|
||||
|
||||
CHAR(n) ist geeignet f<>r die Speicherung von Zeichenketten, die alle
|
||||
die gleiche L<>nge haben. Bitte beachten Sie, dass CHAR(n) automatisch
|
||||
Zeichenketten bis zur definierten Feldl<64>nge mit Leerzeichen ausf<73>llt,
|
||||
w<>hrend bei VARCHAR(n) nur die tats<74>chlich eingegebene Zeichenkette
|
||||
gespeichert wird.
|
||||
|
||||
BYTEA ist f<>r bin<69>re Daten, besonders f<>r Werte, die NULL-Bytes haben.
|
||||
|
||||
Alle der hier erw<72>hnten Typen weisen <20>hnliche Performanzeigenschaften
|
||||
auf.
|
||||
|
||||
4.11.1) Wie erzeuge ich ein serielles Feld mit automatischer Erh<72>hung des
|
||||
Wert?
|
||||
|
||||
PostgreSQL bietet einen SERIAL-Datentyp. Dieser erzeugt automatisch
|
||||
eine Sequenz auf die angegebene Spalte. Zum Beispiel:
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
)
|
||||
|
||||
wird automatisch in:
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
|
||||
umgewandelt.
|
||||
|
||||
Die create_sequence Man-Page liefert weitere Informationen <20>ber
|
||||
Sequenzen.
|
||||
|
||||
4.11.2) Wie bekomme ich den Wert einer SERIAL-Sequenz?
|
||||
|
||||
Eine M<>glichkeit w<>re, mit der nextval()-Funktion den n<>chsten
|
||||
SERIAL-Wert von dem Sequenzobjekt vor der Auszuf<75>hrung einer
|
||||
INSERT-Anweisung anzufordern und ihn dann explizit in die
|
||||
INSERT-Anweisung einzubinden. Anhand der Beispieltabelle in 4.11.1
|
||||
k<>nnte dieser Vorgang in einer Pseudosprache so aussehen:
|
||||
new_id = output of execute("SELECT nextval('person_id_seq')");
|
||||
execute("INSERT INTO person (id, name) VALUES (new_id, 'Blaise Pascal')");
|
||||
|
||||
Danach st<73>nde der neue Wert in der Variablen new_id f<>r die Verwendung
|
||||
in weiteren Abfragen zur Verf<72>gung, zum Beispiel als Fremdschl<68>ssel
|
||||
zur Tabelle 'person'). Bitte beachten Sie, dass der Name des
|
||||
automatisch erstellten SEQUENCE-Objektes folgenden Name hat:
|
||||
<20>table<6C>_<EFBFBD>serialcolumn<6D>_seq wobei 'table' und 'serialcolumn' die Namen
|
||||
der jeweils betreffenden Tabelle / Spalte darstellen.
|
||||
|
||||
Als weitere M<>glichkeit k<>nnen Sie nach einer INSERT-Anweisung den
|
||||
automatisch eingef<65>gten SERIAL-Wert mit der currval()-Funktion
|
||||
zur<75>ckgeben lassen:
|
||||
execute("INSERT INTO person (id, name) VALUES (new_id, 'Blaise Pascal')");
|
||||
new_id = output of execute("SELECT currval('person_id_seq')");
|
||||
|
||||
4.11.3) F<>hrt currval() zu einer Race-Condition mit anderen Nutzern?
|
||||
|
||||
Nein. currval() liefert einen Wert zur<75>ck, der von Ihrer
|
||||
Datenbank-Session bestimmt wird, und der anderen Sessionen nicht zur
|
||||
Verf<72>gung steht.
|
||||
|
||||
4.11.4) Warum werden die Sequenzwerte nach einem Transaktionsabbruch nicht
|
||||
zur<75>ckgesetzt? Warum gibt es L<>cken in der Nummerierung meiner
|
||||
Sequenz-/SERIAL-Spalte?
|
||||
|
||||
Um die gleichzeitige Abarbeitung von Transaktionen zu verbessern,
|
||||
werden Sequenzen gerade nicht f<>r andere Transaktionen gesperrt,
|
||||
sondern die Sequenznummern werden den laufenden Transaktionen sofort
|
||||
zugeteilt. L<>cken in der Sequenznummerierung werden durch abgebrochene
|
||||
Transaktionen verursacht.
|
||||
|
||||
4.12) Was ist ein OID? Was ist ein CTID?
|
||||
|
||||
Jede Zeile, die in PostgreSQL erzeugt wird, bekommt eine eindeutige
|
||||
OID, sofern die Tabelle nicht mit der Option WITHOUT OIDS angelegt
|
||||
wurde. OIDs sind automatisch zugewiesene 4-Byte-Integer, die innerhalb
|
||||
der gesamten Datenbank einmalig sind. Allerdings laufen sie bei einem
|
||||
Wert von ungef<65>hr 4 Milliarden <20>ber. PostgreSQL verwendet OIDs, um
|
||||
seine interne Systemtabellen zu verbinden.
|
||||
|
||||
Um einmalige Idenfikatoren in Datentabellen zu erstellen, wird
|
||||
allerdings empfohlen, statt OIDs Werte zu verwenden, die vonSERIAL-
|
||||
Sequenzen erzeugt werden. SERIAL-Sequenzen sind innerhalb einer
|
||||
Tabelle einmalig und daher weniger anf<6E>llig f<>r <20>berl<72>ufe. Au<41>erdem
|
||||
k<>nnen 8-Byte-Sequenzwerte mit SERIAL8 erzeugt werden.
|
||||
|
||||
CTIDs werden benutzt, um bestimmte physikalische Zeilen durch Block
|
||||
und Offset Werte zu identifizieren. CTIDs ver<65>ndern sich, sobald
|
||||
Zeilen ver<65>ndert oder zur<75>ckgeladen werden. Sie werden in
|
||||
Indexeintr<74>gen benutzt um auf die physikalischen Zeilen zu zeigen.
|
||||
|
||||
4.13) Wieso bekomme ich einen Fehler: "ERROR: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
|
||||
Wahrscheinlich gibt es keinen virtuellen Speicher mehr in Ihrem System
|
||||
oder Ihr Kernel hat niedrige H<>chstgrenzen f<>r bestimmte Ressourcen.
|
||||
Probieren Sie vor dem Start von postmaster folgendes:
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
Je nach benutzter Shell wird nur einer dieser Befehle erfolgreich
|
||||
ausgef<65>hrt werden. Auf jedem Fall wird die Grenze des Datensegments
|
||||
f<>r Prozesse erh<72>ht werden und eventuell die erfolgreiche Ausf<73>hrung
|
||||
der Abfrage erm<72>glichen. Falls Sie ein Problem mit dem SQL-CLient
|
||||
haben, weil das Backend zu viele Daten zur<75>ckliefert, versuchen Sie
|
||||
dies vor dem Start des SQL-Clients.
|
||||
|
||||
4.14) Wie kann ich feststellen, welche PostgreSQL-Version bei mir l<>uft?
|
||||
|
||||
Geben Sie in psql SELECT VERSION(); ein.
|
||||
|
||||
4.15) Wie kann ich eine Spalte erstellen, deren Default-Wert immer die
|
||||
aktuelle Uhrzeit enthalten soll?
|
||||
|
||||
Dazu verwenden Sie CURRENT_TIMESTAMP:
|
||||
CREATE TABLE test (x INT, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
|
||||
4.16) Wie f<>hre ich eine OUTER JOIN durch?
|
||||
|
||||
PostgreSQL unterst<73>tzt OUTER JOINs nach dem SQL- Standardsyntax. Hier
|
||||
zwei Beispiele:
|
||||
SELECT *
|
||||
FROM tabelle_1 t1
|
||||
LEFT OUTER JOIN tabelle_2 t2 ON (t1.spalte = t2.spalte)
|
||||
|
||||
bzw.:
|
||||
SELECT *
|
||||
FROM tabelle_1 t1
|
||||
LEFT OUTER JOIN tabelle_2 t2 USING (spalte)
|
||||
|
||||
Diese identischen Abfragen verkn<6B>pfen tabelle_1 mit tabelle_2 <20>ber die
|
||||
Spalte 'spalte' und geben au<61>erdem alle unverkn<6B>pften Zeilen in
|
||||
tabelle_1 (diejenigen, die keine Entsprechung in tabelle_2 haben)
|
||||
zur<75>ck. Ein RIGHT JOIN w<>rde hingegen alle unverkn<6B>pften Zeilen in
|
||||
tabelle_2 hinzuf<75>gen und ein FULL JOIN w<>rde alle verkn<6B>pften Zeilen
|
||||
sowie jeweils alle unverkn<6B>pften Zeilen aus den beiden Tabellen
|
||||
zur<75>ckliefern. Die Angabe von OUTER ist nicht zwingend und kann in
|
||||
LEFT, RIGHT und FULL-Verkn<6B>pfungen weggelassen werden. Normale
|
||||
Verkn<6B>pfungen sind INNER JOINs.
|
||||
|
||||
4.17) Wie kann ich Abfragen <20>ber mehrere Datenbanken hinweg ausf<73>hren?
|
||||
|
||||
Es gibt keinen Weg, innerhalb einer Abfrage auf mehr als eine
|
||||
Datenbank zuzugreifen. Da PostgreSQL datenbank-spezifische
|
||||
Systemkataloge l<>dt, ist eine datenbank<6E>bergreifende Abfrage nicht
|
||||
m<>glich.
|
||||
|
||||
contrib/dblink ist eine Erweiterung, die datenbank<6E>bergreifende
|
||||
Abfragen <20>ber Funktionsaufrufe erm<72>glicht.
|
||||
|
||||
4.18) Wie kann ich mehrere Zeilen bzw. Spalten von einer Funktion zur<75>ckgeben
|
||||
lassen?
|
||||
|
||||
Funktionen k<>nnen mehrere Zeilen und Spalten zur<75>ckgeben, vgl.:
|
||||
http://www.postgresql.org/docs/techdocs.17.
|
||||
|
||||
4.19) Warum bekomme ich eine Fehlermeldung wie "relation with OID ##### does
|
||||
not exist" wenn ich tempor<6F>re Tabellen in PL/PgSQL-Funktionen benutze?
|
||||
|
||||
In PostgreSQL-Versionen vor 8.3 verarbeitet PL/PgSQL Funktionen in
|
||||
einer Cache. Dies hat eine unangenehme Nebenwirkung, n<>mlich dass wenn
|
||||
eine PL/PgSQL-Funktion auf eine tempor<6F>re Tabelle zugreift, und diese
|
||||
Tabelle anschlie<69>end gel<65>scht bzw. neu erstellt wird, die Funktion
|
||||
fehlschlagen wird, da die gecachten Funktionsinhalte noch auf die alte
|
||||
tempor<6F>re Tabelle zeigen. Die L<>sung f<>r diese Probleme besteht darin,
|
||||
in der PL/PgSQL- Funktion mittels EXECUTE auf tempor<6F>re Tabellen
|
||||
zuzugreifen. Dies bewirkt, dass bei jedem Funktionsruf die betreffende
|
||||
Abfrage neu geparst wird.
|
||||
|
||||
Dieses Problem taucht in PostgreSQL 8.3 und sp<73>teren Versionen nicht
|
||||
mehr auf.
|
||||
|
||||
4.20) Welche Replikationsl<73>sungen gibt es?
|
||||
|
||||
Der Begriff "replikation" umfasst mehrere verschiedene Technologien,
|
||||
jede mit eigenen Vor- und Nachteilen.
|
||||
|
||||
Mit "Master/slave"-Replikation werden <20>nderungen in einer
|
||||
Hauptdatenbank durchgef<65>hrt und an "Sklaven" verteilt, die im
|
||||
Nur-Lese-Modus arbeiten. Die popul<75>rste L<>sung f<>r PostgreSQL ist
|
||||
Slony-I.
|
||||
|
||||
"Multi-master replication" erm<72>glicht sowohl lesende als auch
|
||||
schreibende Zugriffe <20>ber mehrere Datenbank-Server hinweg. Allerdings
|
||||
hat diese Art von Replikation eine negative Auswirkung auf die
|
||||
Performanz durch die Notwendigkeit, <20>nderungen zwischen Servern zu
|
||||
synchronisieren. Pgcluster ist die popul<75>rste freie L<>sung f<>r
|
||||
PostgreSQL.
|
||||
|
||||
Es gibt auch einige kommerzielle und hardware-basierte
|
||||
Replikationsl<73>sungen f<>r verschiedene Arten der Replikation.
|
||||
|
||||
4.21) Warum werden die Tabellen- und Spaltennamen in meiner Abfrage nicht
|
||||
erkannt? Warum werden Gro<72>buchstaben umgewandelt?
|
||||
|
||||
Die h<>ufigste Ursache ist die Verwendung von G<>nsef<65><66>chen bei der
|
||||
Anlegung von Tabellen, z.B.:
|
||||
CREATE TABLE "Tabelle"
|
||||
("SPALTE1" INT)
|
||||
|
||||
Dadurch werden Tabellen- und Spaltennamen (sog. Identifikatoren) in
|
||||
genau der Schreibweise gespeichert (vgl. Dokumentation), was dazu
|
||||
f<>hrt, dass man sie danach immer in G<>nsef<65><66>chen angeben muss. Im
|
||||
obigen Beispiel muss man also immer etwa SELECT * FROM "Tabelle"
|
||||
verwenden. Um dieses Problem zu vermeiden, m<>ssen Sie immer eines der
|
||||
folgenden Punkte beachten:
|
||||
* bei der Tabellenanlegung keine G<>nsef<65><66>chen verwenden;
|
||||
* in Identifikatoren nur Kleinschreibung verwenden;
|
||||
* immer Identifikatoren mit G<>nsef<65><66>chen versehen
|
||||
_________________________________________________________________
|
||||
|
||||
Anmerkungen des <20>bersetzers
|
||||
|
||||
Die englische Vorlage dieser FAQ wird st<73>ndig <20>berarbeitet. Daher
|
||||
liegt die <20>bersetzung nicht immer auf dem aktuellsten Stand.
|
||||
|
||||
Die aktuellste Version der deutschen <20>bersetzung befindet sich immer
|
||||
unter http://sql-info.de/de/postgresql/FAQ_german.html. Diese
|
||||
"Arbeitsversion" enth<74>lt eventuell <20>nderungen, die noch nicht auf der
|
||||
PostgreSQL-Website eingebunden worden sind.
|
||||
|
||||
<20>ber Verbesserungshinweise und Korrekturvorschl<68>ge sowie
|
||||
Verst<73>ndnisfragen zum Inhalt der FAQ freue ich mich. Ich nehme auch
|
||||
allgemeine Fragen zu PostgreSQL gerne entgegen, verweise jedoch auf
|
||||
die Mailing-Listen als schnelle und zuverl<72>ssige Anlaufstellen.
|
||||
1234
doc/FAQ_hungarian
1234
doc/FAQ_hungarian
File diff suppressed because it is too large
Load Diff
1126
doc/FAQ_japanese
1126
doc/FAQ_japanese
File diff suppressed because it is too large
Load Diff
1279
doc/FAQ_polish
1279
doc/FAQ_polish
File diff suppressed because it is too large
Load Diff
988
doc/FAQ_russian
988
doc/FAQ_russian
@ -1,988 +0,0 @@
|
||||
|
||||
Otvety na chasto zadavaemye voprosy po PostgreSQL
|
||||
|
||||
Data poslednego obnovleniya: Sreda 25 iyunya 23:54:14 EDT 2008
|
||||
|
||||
Anglijskij variant soprovozhdaet: Bryus Mom'yan (Bruce Momjian)
|
||||
(bruce@monjian.us)
|
||||
|
||||
Pereviol na russkij: Viktor Vislobokov (admin@postgresql.ru.net)
|
||||
|
||||
Samuyu svezhuyu anglijskuyu versiyu dokumenta mozhno najti na
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ.html.
|
||||
|
||||
Samuyu svezhuyu russkuyu versiyu dokumenta mozhno najti na
|
||||
http://postgresql.ru.net/docs/FAQ_russian.html.
|
||||
|
||||
Otvety na voprosy specifichnye dlya konkretnyh platform mozhno najti
|
||||
na http://www.postgresql.org/docs/faq/.
|
||||
_________________________________________________________________
|
||||
|
||||
Obschie voprosy
|
||||
|
||||
1.1) CHto takoe PostgreSQL? Kak proiznositsya `eto nazvanie? CHto
|
||||
takoe Postgres?
|
||||
1.2) Kto upravlyaet PostgreSQL?
|
||||
1.3) Kakovy avtorskie prava na PostgreSQL?
|
||||
1.4) Na kakih platformah rabotaet PostgreSQL?
|
||||
1.5) Gde mozhno vzyat' PostgreSQL?
|
||||
1.6) Kakaya versiya naibolee svezhaya?
|
||||
1.7) Gde poluchit' podderzhku?
|
||||
1.8) Kak mne soobschit' ob oshibke?
|
||||
1.9) Kak najti informaciyu ob izvestnyh oshibkah ili otsutstvuyuschih
|
||||
vozmozhnostyah?
|
||||
1.10) Kakaya dokumentaciya imeetsya v nalichii?
|
||||
1.11) Kak nauchit'sya SQL?
|
||||
1.12) Kak mne otpravit' ispravlenie ili prisoedinitsya k komande
|
||||
razrabotchikov?
|
||||
1.13) Kak sravnit' PostgreSQL s drugimi SUBD? Mozhet li PostgreSQL
|
||||
byt' vstroennoj?
|
||||
1.14) Budet li PostgreSQL rabotat' s poslednimi izmeneniyami, v raznyh
|
||||
stranyh, kasayuschimisya dnevnogo vremeni?
|
||||
1.15) Kak mne otpisat'sya ot spiskov rassylki PostgreSQL? Kak
|
||||
izbezhat' polucheniya dubliruyuschihsya soobschenij?
|
||||
|
||||
Voprosy pol'zovatelej po klientskoj chasti
|
||||
|
||||
2.1) Kakie interfejsy est' dlya PostgreSQL?
|
||||
2.2) Kakie instrumenty suschestvuyut dlya ispol'zovaniya PostgreSQL
|
||||
cherez Web?
|
||||
2.3) Est' li u PostgreSQL graficheskij interfejs pol'zovatelya?
|
||||
|
||||
Voprosy administrirovaniya
|
||||
|
||||
3.1) Kak mne ustanovit' PostgreSQL v mesto otlichnoe ot
|
||||
/usr/local/pgsql?
|
||||
3.2) Kak mne upravlyat' soedineniyami ot drugih komp'yuterov?
|
||||
3.3) Kakie nastrojki mne nuzhno sdelat' dlya uluchsheniya
|
||||
proizvoditel'nosti?
|
||||
3.4) Kakie vozmozhnosti dlya otladki est' v nalichii?
|
||||
3.5) Pochemu ya poluchayu soobschenie "Sorry, too many clients" kogda
|
||||
pytayus' podklyuchit'sya k baze?
|
||||
3.6) Kak vypolnit' obnovlenie PostgreSQL?
|
||||
3.7) Kakoe komp'yuternoe "zhelezo" ya dolzhen ispol'zovat'?
|
||||
|
||||
Voprosy `ekspluatacii
|
||||
|
||||
4.1) Kak vypolnit' SELECT tol'ko dlya neskol'kih pervyh strochek
|
||||
zaprosa? Dlya proizvol'noj stroki?
|
||||
4.2) Kak mne najti kakie tablicy, indeksy, bazy dannyh i pol'zovateli
|
||||
suschestvuyut? Kak mne uvidet' zaprosy, kotorye ispol'zuet psql dlya
|
||||
polucheniya `etoj informacii?
|
||||
4.3) Kak izmenit' tip dannyh kolonki?
|
||||
4.4) Kakovy maksimal'nye razmery dlya strok v tablice, tablic i bazy
|
||||
dannyh?
|
||||
4.5) Kak mnogo diskovogo prostranstva v baze dannyh nuzhno dlya
|
||||
sohraneniya dannyh iz obychnogo tekstovogo fajla?
|
||||
4.6) Pochemu moi zaprosy rabotayut medleno? Pochemu oni ne ispol'zuyut
|
||||
moi indeksy?
|
||||
4.7) Kak posmotret' na to, kak optimizator vypolnyaet moj zapros?
|
||||
4.8) Kak mne vypolnit' poisk regulyarnogo vyrazheniya i poisk
|
||||
nezavisimyj ot registra bukv poisk regulyarnogo vyrazheniya? Kak mne
|
||||
ispol'zovat' indeks dlya poiska nezavisimogo ot registra bukv?
|
||||
4.9) Kak mne opredelit', chto znachenie polya v kakom-libo zaprose
|
||||
ravno NULL? Kak mne soedinit' vozmozhnye NULL? Mogu ya sortirovat'
|
||||
polya NULL ili net?
|
||||
4.10) Kakovy otlichiya mezhdu raznymi simvol'nymi tipami?
|
||||
4.11.1) Kak mne sozdat' pole serial/s-avto-uvelicheniem?
|
||||
4.11.2) Kak mne poluchit' znachenie pri vstavke SERIAL?
|
||||
4.11.3) Ne mozhet li poluchit'sya tak, chto ispol'zovanie currval() i
|
||||
nextval() privedet k zaciklirovaniyu s drugimi pol'zovatelyami?
|
||||
4.11.4) Pochemu chisla iz moej posledovatel'nosti ne ispol'zuyutsya
|
||||
snova pri otmene tranzakcii? Pochemu sozdayutsya razryvy pri numeracii
|
||||
v kolonke, gde ya ispol'zuyu posledovatel'nost'/SERIAL?
|
||||
4.12) CHto takoe OID? CHto takoe CTID?
|
||||
4.13) Pochemu ya poluchayu oshibku "ERROR: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
4.14) Kak mne uznat', kakaya versiya PostgreSQL zapuschena?
|
||||
4.15) Kak mne sozdat' kolonku kotoraya po umolchaniyu budet soderzhat'
|
||||
tekuschee vremya?
|
||||
4.16) Kak vypolnit' vneshnee svyazyvanie?
|
||||
4.17) Kak vypolnyat' zaprosy, ispol'zuyuschie neskol'ko baz dannyh?
|
||||
4.18) Kak mne vernut' iz funkcii neskol'ko strok tablicy?
|
||||
4.19) Pochemu ya poluchayu oshibku "relation with OID #### ne
|
||||
suschestvuet", kogda obraschayuts' k vremennym tablicam v funkciyah
|
||||
PL/PgSQL?
|
||||
4.20) Kakie est' resheniya dlya replikacii?
|
||||
4.21) Pochemu imena tablicy i kolonok ne raspoznayutsya v v moiom
|
||||
zaprose? Pochemu ne sohranyayutsya zaglavnye bukvy?
|
||||
_________________________________________________________________
|
||||
|
||||
Obschie voprosy
|
||||
|
||||
1.1) CHto takoe PostgreSQL? Kak proiznositsya `eto nazvanie? CHto takoe
|
||||
Postgres?
|
||||
|
||||
PostgreSQL proiznositsya Post-Gres-Q-L (Post-Gres-K'yu-`El). (Dlya
|
||||
osobo lyubopytstvuyuschih kak proiznosit' "PostgreSQL", suschestvuet
|
||||
audio-fajl).
|
||||
|
||||
PostgreSQL - `eto ob"ektno-relyacionnaya sistema upravleniya bazami
|
||||
dannyh (SUBD), kotoraya imeet tradicionnye vozmozhnosti kommercheskih
|
||||
SUBD s rasshireniyami, kotorye est' v SUBD novogo pokoleniya.
|
||||
PostgreSQL - `eto svobodnoe i polnost'yu otkrytoe programmnoe
|
||||
obespechenie.
|
||||
|
||||
Razrabotku PostgreSQL vypolnyaet komanda razrabotchikov, razbrosannaya
|
||||
po vsemu miru i svyazannaya cherez Internet. Razrabotka yavlyaetsya
|
||||
obschestvennym proektom i ne upravlyaetsya kakoj-libo kompaniej.
|
||||
Podrobnosti smotrite v FAQ dlya razrabotchikov,
|
||||
http://www.postgresql.org/docs/faqs.FAQ_DEV.html
|
||||
|
||||
Postgres -- `eto shiroko ispol'zuemoe sokraschenie dlya PostgreSQL.
|
||||
Pervonachal'nym imenem proekta v Berkli bylo Postgres i `etot nik
|
||||
teper' naibolee populyaren v razgovorah o PostgreSQL po sravneniyu s
|
||||
drugimi. Esli vam trudno polnost'yu progovarivat' 'PostgreSQL', mozhno
|
||||
prosto govorit' 'Postgres'.
|
||||
|
||||
1.2) Kto upravlyaet PostgreSQL?
|
||||
|
||||
Esli vy ischite kakogo-to osobennogo cheloveka, central'nyj komitet
|
||||
ili upravlyayuschuyu kompaniyu, to naprasno --- ih net. U nas est'
|
||||
yadro komiteta i razrabotchikov, rabotayuschih s CVS, no `eti gruppy
|
||||
sluzhat bol'she dlya administrativnyh celej, chem dlya upravleniya.
|
||||
Proekt napryamuyu funkcioniruet s pomosch'yu soobschestva
|
||||
razrabotchikov i pol'zovatelej, k kotoromu mozhet prisoedinitsya
|
||||
kazhdyj. Vsio chto nuzhno -- `eto podpisat'sya na spiski rassylki i
|
||||
uchastvovat' v diskussiyah. (Podrobnosti o tom kak vklyuchit'sya v
|
||||
razrabotku PostgreSQL smotrite v FAQ dlya razrabotchikov.)
|
||||
|
||||
1.3) Kakovy avtorskie prava na PostgreSQL?
|
||||
|
||||
PostgreSQL rasprostranyaetsya po klassicheskoj licenzii BSD. `Eta
|
||||
licenziya ne soderzhit ogranichenij na to, kak budet ispol'zovat'sya
|
||||
ishodnyj kod. Nam nravitsya `eta licenziya i u nas net namerenij eio
|
||||
menyat'. Vot `eta licenziya BSD, kotoruyu my ispol'zuem:
|
||||
|
||||
Sistema Upravleniya Bazami Dannyh PostgreSQL
|
||||
|
||||
Portions copyright (c) 1996-2008, PostgreSQL Global Development Group
|
||||
Portions Copyright (c) 1994-1996 Regents of the University of
|
||||
California
|
||||
|
||||
Predostavlyayutsya prava na ispol'zovanie, kopirovanie, izmenenie i
|
||||
rasprostranenie dannogo programmnogo obespecheniya i ego dokumentacii
|
||||
dlya lyubyh celej, besplatno i bez podpisaniya kakogo-libo
|
||||
soglasheniya, pri uslovii chto dlya kazhdoj kopii budut predostavleny
|
||||
dannoe vyshe zamechanie ob avtorskih pravah, tekuschij paragraf i dva
|
||||
sleduyuschih paragrafa.
|
||||
|
||||
KALIFORNIJSKIJ UNIVERSITET NE NESET NIKAKOJ OTVETSTVENNOSTI ZA LYUBYE
|
||||
POVREZHDENIYA, VKLYUCHAYA POTERYU DOHODA, NANESENNYE PRYAMYM ILI
|
||||
NEPRYAMYM, SPECIAL'NYM ILI SLUCHAJNYM ISPOL'ZOVANIEM DANNOGO
|
||||
PROGRAMMNOGO OBESPECHENIYA ILI EGO DOKUMENTACII, DAZHE ESLI
|
||||
KALIFORNIJSKIJ UNIVERSITET BYL IZVESCHEN O VOZMOZHNOSTI TAKIH
|
||||
POVREZHDENIJ.
|
||||
|
||||
KALIFORNIJSKIJ UNIVERSITET SPECIAL'NO OTKAZYVAZYVAETSYA PREDOSTAVLYAT'
|
||||
LYUBYE GARANTII, VKLYUCHAYA, NO NE OGRANICHIVAYAS' TOL'KO `ETIMI
|
||||
GARANTIYAMI: NEYAVNYE GARANTII PRIGODNOSTI TOVARA ILI PRIGODNOSTI DLYA
|
||||
OTDEL'NOJ CELI. DANNOE PROGRAMMNOE OBESPECHENIE PREDOSTAVLYAETSYA NA
|
||||
OSNOVE PRICIPA "KAK EST'" I KALIFORNIJSKIJ UNIVERSITET NE OBYAZAN
|
||||
PREDOSTAVLYAT' SOPROVOZHDENIE, PODDERZHKU, OBNOVLENIYA, RASSHIRENIYA
|
||||
ILI IZMENENIYA.
|
||||
|
||||
1.4) Na kakih platformah rabotaet PostgreSQL?
|
||||
|
||||
Obychno, PostgreSQL mozhet rabotat' na lyuboj sovremennoj platforme
|
||||
sovmestimoj s Unix. V instrukcii po ustanovke, vy najdete spisok teh
|
||||
platform, na kotoryh byli provedeny testovye zapuski PostgreSQL k
|
||||
momentu vyhoda dannoj versii.
|
||||
|
||||
PostgreSQL takzhe rabotaet na operacionnyh sistemah Microsoft Windows,
|
||||
osnovannyh na NT, takih kak Win2000 SP4, WinXP i Win2003. Paket
|
||||
installyatora dostupen po adresu
|
||||
http://www.postgresql.org/download/windows. Versii Windows, osnovannye
|
||||
na MS-DOS (Win95, Win98, WinMe) mogut zapuskat' PostgreSQL s
|
||||
pomosch'yu Cygwin.
|
||||
|
||||
Takzhe suschestvuet versiya sportirovannaya pod Novell Netware 6 na
|
||||
http://developer.novell.com/wiki/index.php/Postgresql, i versiya dlya
|
||||
OS/2 (eComStation) na
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgre
|
||||
SQL&stype=all&sort=type&dir=%2F.
|
||||
|
||||
1.5) Gde mozhno vzyat' PostgreSQL?
|
||||
|
||||
CHerez brauzer, ispol'zuya http://www.postgresql.org/ftp/ i cherez
|
||||
ftp, ispol'zuya ftp://ftp.postgresql.org/pub/.
|
||||
|
||||
1.6) Kakaya versiya naibolee svezhaya?
|
||||
|
||||
Poslednij vypusk PostgreSQL - `eto versiya 8.3.3
|
||||
|
||||
My planiruem vypuskat' novye starshie versii kazhdyj god, a mladshie
|
||||
versii kazhdye neskol'ko mesyacev.
|
||||
|
||||
1.7) Gde poluchit' podderzhku?
|
||||
|
||||
Soobschestvo PostgreSQL predostavlyaet pomosch' mnozhestvu
|
||||
pol'zovatelej cherez E-mail. Osnovnoj web-sajt dlya podpiski na spiski
|
||||
rassylki po E-mail `eto: http://www.postgresql.org/community/lists/.
|
||||
Horoshim mestom dlya togo, chtoby nachat' zadavat' voprosy
|
||||
yavlyayutsya spiski general (obschie voprosy) ili bugs (oshibki).
|
||||
|
||||
Glavnym IRC kanalom yavlyaetsya #postgreql, raspolozhennyj na servere
|
||||
Freenode (irc.freenode.net). CHtoby podklyuchit'sya, vy mozhete
|
||||
ispol'zovat' v Unix vyzov programmy irc -c '#postgresql' "$USER"
|
||||
irc.freenode.net ili lyuboj drugoj IRC klient. Na `etom zhe servere
|
||||
suschestvuyut kanaly na ispanskom (#postgresql-es), francuzskom
|
||||
(#postgresqlfr) i brazil'skom (#postgresql-br) yazykah. Takzhe
|
||||
suschestvuet kanal po PostgreSQL na servere EFNet.
|
||||
|
||||
Spisok kommercheskoj podderzhki kompanij dostupen na
|
||||
http://www.postgresql.org/support/professional_support.
|
||||
|
||||
1.8) Kak mne soobschit' ob oshibke?
|
||||
|
||||
Posetite stranichku so special'noj formoj otchiota ob oshibke v
|
||||
PostgreSQL po adresu: http://www.postgresql.org/support/submitbug.
|
||||
Takzhe prover'te nalichie bolee svezhej versii PostgreSQL na nashem
|
||||
FTP sajte ftp://ftp.postgresql.org/pub/.
|
||||
|
||||
Na oshibki, uvedomlenie o kotoryh byli sdelany cherez special'nuyu
|
||||
formu ili otpravlennye v kakoj-libo spisok rassylki PostgreSQL,
|
||||
obychno generiruetsya odin iz sleduyuschih otvetov:
|
||||
* `Eto ne oshibka i pochemu
|
||||
* `Eto izvestnaya oshibka i ona uzhe est' v spiske TODO
|
||||
* Dannaya oshibka byla ispravlena v tekuschem vypuske
|
||||
* Dannaya oshibka byla ispravlena, no ispravlenie poka ne popalo v
|
||||
oficial'nyj vypusk
|
||||
* Zaprashivaetsya bolee detal'naya informaciya:
|
||||
+ Operacionnaya sistema
|
||||
+ Versiya PostgreSQL
|
||||
+ Test, vosproizvodyaschij oshibku
|
||||
+ Otladochnaya informaciya
|
||||
+ Vyvod backtrace otladchika
|
||||
* `Eto novaya oshibka. Mozhet proizojti sleduyuschee:
|
||||
+ Budet sozdano ispravlenie, kotoroe budet vklyucheno v
|
||||
sleduyuschij vypusk
|
||||
+ Oshibka ne mozhet byt' ispravlena nemedlenno i budet
|
||||
dobavlena v spisok TODO
|
||||
|
||||
1.9) Kak najti informaciyu ob izvestnyh oshibkah ili otsutstvuyuschih
|
||||
vozmozhnostyah?
|
||||
|
||||
PostgreSQL podderzhivaet rasshirennyj podklass SQL:2003. Smotrite nash
|
||||
spisok TODO na predmet izvestnyh oshibok, otsutstvuyuschih
|
||||
vozmozhnostej i buduschih planov.
|
||||
|
||||
Na zapros kakoj-libo vozmozhnosti obychno prihodyat sleduyuschie
|
||||
otvety:
|
||||
* Dannaya vozmozhnost' uzhe est' v spiske TODO
|
||||
* Dannaya vozmozhnost' nezhelatel'na potomu chto:
|
||||
+ Ona dubliruet suschestvuyuschuyu funkcional'nost', kotoraya
|
||||
sleduet standartu SQL
|
||||
+ Dannaya vozmozhnost' sil'no uslozhnila by kod, no dala by
|
||||
malen'kuyu vygodu
|
||||
+ Dannaya vozmozhnost' nebezopasna ili nenadiozhna
|
||||
* Dannaya novaya vozmozhnost' dobavlena v spisok TODO
|
||||
|
||||
PostgreSQL ne ispol'zuet kakuyu-libo sistemu otslezhivaniya oshibok,
|
||||
potomu chto my obnaruzhili, chto ispol'zovanie pryamogo obrascheniya
|
||||
po `elektronnoj pochte i obnovlyaemogo spiska TODO yavlyaetsya bolee
|
||||
`effektivnym. Na praktike, oshibki v programmnom obespechenii
|
||||
sohranyayutsya ochen' nedolgo, a oshibki, kotorye vazhny bol'shomu
|
||||
kolichestvu pol'zovatelej ispravlyayutsya momental'no. Est' tol'ko
|
||||
odno mesto, gde mozhno najti vse izmeneniya, uluchsheniya i
|
||||
ispravleniya, sdelannye v vypuske PostgreSQL - `eto zhurnaly
|
||||
soobschenij sistemy kontrolya versij CVS. Dazhe zamechaniya k vypuskam
|
||||
ne soderzhat vse izmeneniya, sdelannye v programmnom obespechenii.
|
||||
|
||||
1.10) Kakaya dokumentaciya imeetsya v nalichii?
|
||||
|
||||
PostgreSQL soderzhit mnogo dokumentacii, vklyuchaya bol'shoe
|
||||
rukovodstvo, stranicy `elektronnogo rukovodstva man i nekotorye
|
||||
malen'kie testovye primery. Smotrite v katalog /doc. Vy takzhe mozhete
|
||||
prosmatrivat' dokumentaciyu v Internet po adresu
|
||||
http://www.postgresql.org/docs.
|
||||
|
||||
Suschestvuet dve knigi po PostgreSQL dostupnye po adresam
|
||||
http://www.PostgreSQL.org/docs/books/awbook.html i
|
||||
http://www.commandprompt.com/ppbook/. Est' neskol'ko knig po
|
||||
PostgreSQL, kotorye mozhno kupit'. Odnu iz naibolee populyarnyh
|
||||
napisal Korri Duglas (Korry Douglas). Spisok obzorov po `etim knigam
|
||||
dostupen po adresu http://www.postgresql.org/docs/books/. Krome togo,
|
||||
po adresu
|
||||
http://wiki.postgresql.org/wiki/Community_Generated_Articles%2C_Guides
|
||||
%2C_and_Documentation vy mozhete najti kollekciyu tehnicheskih statej,
|
||||
posveschennyh PostgreSQL.
|
||||
|
||||
Klient komandnoj stroki psql imeet neskol'ko komand \d dlya
|
||||
otobrazheniya informacii po tipam, operatoram, funkciyam, agregatam i
|
||||
t.d. - ispol'zujte \? dlya polucheniya spiska dostupnyh komand.
|
||||
|
||||
Nash sajt soderzhit esche bol'she informacii.
|
||||
|
||||
1.11) Kak mne nauchit'sya SQL?
|
||||
|
||||
Vo-pervyh, voz'mite odnu iz knig po PostgreSQL, o kotoryh govorilos'
|
||||
vyshe. Mnogim iz nashih pol'zovatelej takzhe nravitsya kniga The
|
||||
Practical SQL Handbook, Bowman, Judith S., et al., Addison-Wesley.
|
||||
Drugim nravitsya The Complete Reference SQL, Groff et al.,
|
||||
McGraw-Hill.
|
||||
|
||||
Suschestvuet takzhe mnozhestvo prekrasnyh uchebnikov dostupnyh v
|
||||
online:
|
||||
* http://www.intermedia.net/support/sql/sqltut.shtm,
|
||||
* http://sqlcourse.com.
|
||||
* http://www.w3school.com/sql/default.asp
|
||||
* http://mysite.verizon.net/Graeme_Birchall/id1.html
|
||||
|
||||
1.12) Kak mne prislat' ispravlenie ili prisoedinitsya k komande
|
||||
razrabotchikov?
|
||||
|
||||
Smotrite FAQ dlya razrabotchikov.
|
||||
|
||||
1.13) Kak sravnit' PostgreSQL s drugimi SUBD? Mozhet li PostgreSQL byt'
|
||||
vstroennym?
|
||||
|
||||
Suschestvuet neskol'ko metodov sravneniya programmnogo obespecheniya:
|
||||
vozmozhnosti, proizvoditel'nost', nadezhnost', podderzhka i cena.
|
||||
|
||||
Vozmozhnosti
|
||||
PostgreSQL imeet bol'shinstvo vozmozhnostej predstavlennyh v
|
||||
bol'shih kommercheskih SUBD, takie kak: tranzakcii, podzaprosy,
|
||||
triggery, predstavleniya, ssylochnoj celostnosti vtorichnogo
|
||||
klyucha i raznye blokirovki. U nas est' nekotorye vozmozhnosti,
|
||||
kotoryh net u nih: tipy, opredelyaemye pol'zovatelem, mehanizm
|
||||
nasledovaniya, pravila i konkuretnoe mnogoversionnoe upravlenie
|
||||
dlya raboty s soderzhimym blokirovok.
|
||||
|
||||
Proizvoditel'nost'
|
||||
Proizvoditel'nost' PostgreSQL shodna s drugimi kommercheskimi
|
||||
SUBD i s SUBD s otkrytym ishodnym kodom. V kakih-to veschah my
|
||||
bystree, v kakih-to medlennee. Nasha proizvoditel'nosti obychno
|
||||
+/-10% po sravneniyu s drugimi SUBD.
|
||||
|
||||
Nadezhnost'
|
||||
My ponimali, chto nasha SUBD dolzhna byt' nadezhnoj ili ona
|
||||
nichego ne budet stoit'. My staraemsya vypuskat' horosho
|
||||
proverennyj, stabil'nyj kod, kotoryj soderzhit minimum oshibok.
|
||||
Kazhdyj vypusk prohodit stadiyu beta-testirovaniya po krajnej
|
||||
mere v techenii odnogo mesyaca i nasha istoriya vypuskov
|
||||
pokazyvaet chto my mozhem predostavlyat' stabil'nye, monolitnye
|
||||
vypuski, kotorye gotovy k produktivnomu ispol'zovaniyu. My
|
||||
verim, chto my proizvodim proverku ne huzhe, chem u drugih
|
||||
SUBD.
|
||||
|
||||
Podderzhka
|
||||
Nash spisok rassylki predostavlyaet vozmozhmozhnost' obscheniya
|
||||
s bol'shoj gruppoj razrabotchikov i pol'zovatelej, kotorye
|
||||
mogut pomoch' reshit' lyubye voznikshie problemy. V to zhe
|
||||
vremya, my ne garantiruem kakie-libo ispravleniya, no i
|
||||
razrabotchiki kommercheskih SUBD ne vsegda delayut
|
||||
ispravleniya. Pryamoj dostup k razrabotchikam, soobschestvu
|
||||
pol'zovatelej, rukovodstvam i ishodnym tekstam chasto delayut
|
||||
podderzhku PostgreSQL prevoshodyaschej drugie SUBD.
|
||||
Suschestvuet kommercheskaya podderzhka po rezul'tam voznikshih
|
||||
incidentov, kotoraya dostupna dlya teh komu ona nuzhna.
|
||||
(Smotrite Sekciyu 1.7.)
|
||||
|
||||
Cena
|
||||
Nash produkt besplaten kak dlya kommercheskogo tak, i ne dlya
|
||||
kommercheskogo ispol'zovaniya. Vy mozhete dobavlyat' svoj kod v
|
||||
nash produkt bez ogranichenij, za isklyucheniem teh, chto
|
||||
opisyvayutsya v nashej licenzii stilya BSD, kotoraya privedena
|
||||
vyshe.
|
||||
|
||||
PostgreSQL razrabatyvaetsya po arhitekture klient/server, kotoraya
|
||||
trebuet otdel'nyh processov dlya kazhdogo klienta i servera, a takzhe
|
||||
neskol'ko vspomogatel'nyh processov. Mnogie vstraivaemye arhitektury
|
||||
mogut sootvetstvovat' takim trebovaniyam. Odnako, esli vasha
|
||||
vstraivaemaya arhitektura trebuet server baz dannyh dlya zapuska
|
||||
vnutri prikladnogo processa, vy ne mozhete ispol'zovat' Postgres i vam
|
||||
luchshe by vybrat' dlya bazy dannyh kakoe-libo drugoe oblegchennoe
|
||||
reshenie.
|
||||
|
||||
1.14) Budet li PostgreSQL rabotat' s poslednimi izmeneniyami, v raznyh
|
||||
stranyh, kasayuschimisya dnevnogo vremeni?
|
||||
|
||||
Izmeneniya v sohranenii dnevnogo vremeni v SSHA vklyucheny v
|
||||
PostgreSQL versii 8.0.[4+] i vo vse sleduyuschie vypuski, naprimer v
|
||||
8.1. Izmeneniya po Kanade i Zapadnoj Avstralii vklyucheny v 8.0.[10+],
|
||||
8.1.[6+] i vse sleduyuschie vypuski. Vypuski PostgreSQL do 8.0
|
||||
ispol'zuyut informaciyu o sohranenii dnevnogo vremeni iz bazy dannyh
|
||||
vremennyh zon v operacionnoj sisteme.
|
||||
_________________________________________________________________
|
||||
|
||||
1.15) Kak mne otpisat'sya ot spiskov rassylki PostgreSQL? Kak izbezhat'
|
||||
polucheniya dubliruyuschih soobschenij?
|
||||
|
||||
Stranica Majordomo na sajte PostgreSQL pozvolyaet podpisat'sya ili
|
||||
otpisat'sya ot lyubogo iz spiskov rassylki PostgreSQL. (Vam mozhet
|
||||
ponadobitsya vash parol' dlya Majordomo, kotoryj otpravlyaetsya na
|
||||
vash E-mail, chtoby vojti v upravlenie vashimi podpiskami.)
|
||||
|
||||
Vse spiski rassylki PostgreSQL nastarivayutsya tak, chtoby gruppovoj
|
||||
otvet uhodil na adres spiska i na adres avtora soobscheniya. Tak
|
||||
sdelano, chtoby pol'zovateli poluchali otvety na E-mail kak mozhno
|
||||
bystree. Esli vy ne hotite poluchat' dubliruyuschie E-mail
|
||||
soobscheniya iz spiska, v sluchayah kogda vy uzhe poluchili `eti
|
||||
soobscheniya napryamuyu, ustanovite flazhok eliminatecc na stranice
|
||||
Change Settings v Majordomo. Vy takzhe mozhete izbezhat' polucheniya
|
||||
kopij svoih soobschenij dlya samogo sebya, esli snimite flazhok
|
||||
selfcopy.
|
||||
_________________________________________________________________
|
||||
|
||||
Voprosy pol'zovatelej po klientskoj chasti
|
||||
|
||||
2.1) Kakie interfejsy est' dlya PostgreSQL?
|
||||
|
||||
Ustanovka PostgreSQL vklyuchaet tol'ko C i vstroennyj (embedded) C
|
||||
interfejsy. Vse drugie interfejsy yavlyayutsya nezavisimymi proektami
|
||||
i zagruzhayutsya otdel'no; samostoyatel'nost' proektov pozvolyaet im
|
||||
organizovat' sobstvennoe raspisanie vypuskov novyh versij i imet'
|
||||
sobstvennuyu komandu razrabotchikov.
|
||||
|
||||
Nekotorye yazyki programmirovaniya, takie kak PHP vklyuchayut v sebya
|
||||
interfejs k PostgreSQL. Interfejsy dlya takih yazykov kak Perl, TCL,
|
||||
Python i mnogih drugih, dostupny na http://pgfoundry.org.
|
||||
|
||||
2.2) Kakie instrumenty suschestvuyut dlya ispol'zovaniya PostgreSQL cherez
|
||||
Web?
|
||||
|
||||
Prekrasnoe vvedenie vo vzaimodejstvie baz dannyh i Web mozhno najti
|
||||
na: http://www.webreview.com
|
||||
|
||||
Dlya integracii s Web, PHP http://www.php.net yavlyaetsya neplohim
|
||||
interfejsom.
|
||||
|
||||
V slozhnyh sluchayah, mnogie pol'zuyutsya Perl i DBD::Pg s CGI.pm ili
|
||||
mod_perl.
|
||||
|
||||
2.3) Est' li u PostgreSQL graficheskij interfejs pol'zovatelya?
|
||||
|
||||
Dlya PostgreSQL suschestvuet bol'shoe kolichestvo instrumentov s
|
||||
graficheskim interfejsom kak kommercheskih, tak i otkrytyh.
|
||||
Podrobnosti mozhno najti v Dokumentacii soobschestva dlya GUI
|
||||
istrumentov PostgreSQL
|
||||
_________________________________________________________________
|
||||
|
||||
Voprosy administrirovaniya
|
||||
|
||||
3.1) Kak mne ustanovit' PostgreSQL v mesto otlichnoe ot /usr/local/pgsql?
|
||||
|
||||
Zadajte opciyu --prefix kogda zapuskaete configure.
|
||||
|
||||
3.2) Kak mne upravlyat' soedineniyami ot drugih komp'yuterov?
|
||||
|
||||
Po umolchaniyu, PostgreSQL razreshaet tol'ko soedineniya na lokal'noj
|
||||
mashine cherez sokety domena Unix ili TCP/IP soedineniya. Dlya togo,
|
||||
chtoby drugie mashiny smogli podklyuchit'sya k baze vy dolzhny
|
||||
izmenit' listen_addresses v postgresql.conf, razreshit'
|
||||
host-avtorizaciya v fajle $PGDATA/pg_hba.conf i perestartovat' server
|
||||
SUBD.
|
||||
|
||||
3.3) Kakie nastrojki mne nuzhno sdelat' dlya uluchsheniya proizvoditel'nosti?
|
||||
|
||||
Suschestvuet tri glavnyh oblasti, kotorye potencial'no mogut
|
||||
uvelichit' proizvoditel'nost':
|
||||
|
||||
Izmenenie zaprosa
|
||||
`Eto oznachaet modifikaciyu zaprosov dlya polucheniya luchshej
|
||||
proizvoditel'nosti:
|
||||
|
||||
+ Sozdanie indeksov, vklyuchaya indeksy vyrazhenij i
|
||||
chastichnye indeksy
|
||||
+ Ispol'zovanie COPY vmesto mnozhestva INSERT
|
||||
+ Gruppirovka neskol'kih operatorov v edinuyu tranzakciyu dlya
|
||||
umen'sheniya nagruzki pri vypolnenii zaversheniya tranzakcii
|
||||
+ Ispol'zovanie CLUSTER, kogda iz indeksa beriotsya mnozhestvo
|
||||
strok
|
||||
+ Ispol'zovanie LIMIT dlya togo, chtoby vozvraschalas' tol'ko
|
||||
chast' vyvoda ot zaprosa
|
||||
+ Ispol'zovanie Podgotovlennyh (Prepared) zaprosov
|
||||
+ Ispol'zovanie ANALYZE dlya obsluzhivaniya statistiki
|
||||
optimizatora
|
||||
+ Regulyarnoe ispol'zovanie VACUUM ili pg_autovacuum
|
||||
+ Udalenie indeksov vo vremya bol'shih izmenenij dannyh
|
||||
|
||||
Nastrojka servera
|
||||
Nekotorye ustanovki v postgresql.conf vliyayut na
|
||||
proizvoditel'nost'. Podrobnyj polnyj spisok ustanovok sm. v
|
||||
Administration Guide/Server Run-time Environment/Run-time
|
||||
Configuration, a kommentarii sm. v
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_co
|
||||
nf_e.html i
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html.
|
||||
|
||||
Vybor "zheleza" - apparatnogo obespecheniya
|
||||
Vliyanie "zheleza" na proizvoditel'nost' podrobno opisano v
|
||||
http://www.powerpostgresql.com/PerfList/ i
|
||||
http://momjian.us/main/writings/pgsql/hw_performance/index.html
|
||||
.
|
||||
|
||||
3.4) Kakie vozmozhnosti dlya otladki est' v nalichii?
|
||||
|
||||
Est' mnozhestvo ustanovok v nastrojkah servera, nachinayuschihsya na
|
||||
log_* na
|
||||
http://www.postgresql.org/docs/current/interactive/runtime-config-logg
|
||||
ing.html, pozvolyayuschih protokolirovat' zaprosy i statistiku raboty
|
||||
processa, kotoraya ochen' polezna dlya otladki i izmereniya
|
||||
proizvoditel'nosti.
|
||||
|
||||
3.5) Pochemu ya poluchayu soobschenie "Sorry, too many clients" kogda
|
||||
pytayus' podklyuchit'sya k baze?
|
||||
|
||||
Vy dostigli ustanovlennogo po umolchaniyu ogranicheniya v 100 sessij
|
||||
podklyucheniya k baze dannyh. Vam neobhodimo uvelichit' limit na
|
||||
kolichestvo konkurentnyh backend processov dlya vashego servera BD,
|
||||
izmeniv znachenie max_connections v fajle postgresql.conf i
|
||||
perestartovat' server BD.
|
||||
|
||||
3.6) Kak vypolnit' obnovlenie PostgreSQL?
|
||||
|
||||
Sm. informaciyu ob obnovlenii v
|
||||
http://www.postgresql.org/support/versioning i special'nye instrukcii
|
||||
v
|
||||
http://www.postgresql.org/docs/current/static/install-upgrading.html.
|
||||
|
||||
3.7) Kakoe komp'yuternoe "zhelezo" ya dolzhen ispol'zovat'?
|
||||
|
||||
Poskol'ku "zhelezo" personal'nyh komp'yuterov yavlyaetsya naibolee
|
||||
sovmestimym, lyudi sklonny verit', chto takoe "zhelezo" imeet
|
||||
odinakovoe kachestvo. `Eto ne tak. Pamyat' ECC, SCSI i kachestvennye
|
||||
materinskie platy yavlyayutsya bolee nadiozhnymi i imeyut bolee
|
||||
luchshuyu proizvoditel'nost', chem menee dorogoe "zhelezo". PostgreSQL
|
||||
budet rabotat' na lyubom "zheleze", no esli dlya vas vazhny
|
||||
nadiozhnost' i proizvoditel'nost', to s vashej storony budet mudro
|
||||
postavit' sootvetstvuyuschee "zhelezo". Obsudit' raznoe "zhelezo"
|
||||
mozhno v nashih spiskah rassylki.
|
||||
_________________________________________________________________
|
||||
|
||||
Voprosy `ekspluatacii
|
||||
|
||||
4.1) Kak vypolnit' SELECT tol'ko dlya neskol'kih pervyh strochek zaprosa?
|
||||
Proizvol'noj stroki?
|
||||
|
||||
Dlya polucheniya tol'ko neskol'kih strok, esli vy znaete ih
|
||||
kolichestvo na moment vypolneniya SELECT ispol'zujte LIMIT.
|
||||
Esli est' kakoj-libo indeks, kotoryj sovpadaet s ORDER BY, to
|
||||
vozmozhno, chto ves' zapros vypolnen i ne budet. Esli vy ne znaete
|
||||
kolichestva neobhodimyh strok na moment vypolneniya SELECT,
|
||||
ispol'zujte kursor i FETCH.
|
||||
|
||||
To SELECT a random row, use:
|
||||
SELECT col
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1;
|
||||
|
||||
4.2) Kak mne najti kakie tablicy, indeksy, bazy dannyh i pol'zovateli
|
||||
suschestvuyut? Kak mne uvidet' zaprosy, kotorye ispol'zuet psql dlya
|
||||
polucheniya `etoj informacii?
|
||||
|
||||
CHtoby prosmatrivat' tablicy v psql, ispol'zujte komandu \dt. Polnyj
|
||||
spisok komand v psql vy mozhete poluchit', ispol'zuya \?. Krome togo,
|
||||
vy mozhete posmotret' ishodnyj kod psql v fajle
|
||||
pgsql/src/bin/psql/describe.c. On soderzhit komandy SQL kotorye
|
||||
generiruyutsya pri vvode v psql komand, nachinayuschihsya s obratnoj
|
||||
kosoj cherty. Vy takzhe mozhete zapustit' psql s opciej -E tak, chtoby
|
||||
`eta programma vydavala zaprosy, kotorye ona ispol'zuet dlya
|
||||
vypolneniya zadannyh vami komand. PostgreSQL takzhe predostavlyaet SQL
|
||||
sovmestimyj s INFORMATION SCHEMA interfejs, s pomosch'yu kotorogo, vy
|
||||
mozhete sformirovat' zapros na poluchenie informacii o baze dannyh.
|
||||
|
||||
Takzhe suschestvuyut sistemnye tablicy, nachinayuschiesya s pg_.
|
||||
|
||||
Ispol'zujte psql -l dlya polucheniya spiska vseh baz dannyh.
|
||||
|
||||
Takzhe posmotrite fajl pgsql/src/tutorial/syscat.source. On pokazyvaet
|
||||
mnogie iz operatorov SELECT neobhodimyh dlya polucheniya informacii iz
|
||||
sistemnyh tablic bazy dannyh.
|
||||
|
||||
4.3) Kak izmenit' tip dannyh kolonki?
|
||||
|
||||
V 8.0 i bolee pozdnih versiyah, izmenenie tipa kolonki vypolnyaetsya
|
||||
ochen' legko cherez ALTER TABLE ALTER COLUMN TYPE.
|
||||
|
||||
V bolee rannih versiyah sdelajte tak:
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN new_col new_data_type;
|
||||
UPDATE tab SET new_col = CAST(old_col AS new_data_type);
|
||||
ALTER TABLE tab DROP COLUMN old_col;
|
||||
COMMIT;
|
||||
|
||||
4.4) Kakovy maksimal'nye razmery dlya strok v tablice, tablic i bazy dannyh?
|
||||
|
||||
Suschestvuyut sleduyuschie ogranicheniya:
|
||||
|
||||
Maksimal'nyj razmer bazy? neogranichen (suschestvuyut bazy na 32 TB)
|
||||
Maksimal'nyj razmer tablicy? 32 TB
|
||||
Maksimal'nyj razmer stroki? 400 Gb
|
||||
Maksimal'nyj razmer polya? 1 GB
|
||||
Maksimal'noe kolichestvo strok v tablice? neogranicheno
|
||||
Maksimal'noe kolichestvo kolonok v tablice? 250-1600 v zavisimosti ot
|
||||
tipa
|
||||
Maksimal'noe kolichestvo indeksov v tablice? neogranicheno
|
||||
|
||||
Razumeetsya, ponyatie "neogranicheno" na samom dele ogranichivaetsya
|
||||
dostupnym diskovym prostranistvom i razmerami pamyati/svoppinga. Kogda
|
||||
znacheniya perechislennye vyshe neopravdano bol'shie, mozhet
|
||||
postradat' proizvoditel'nost'.
|
||||
|
||||
Maksimal'nyj razmer tablicy v 32 TB ne trebuet chtoby operacionnaya
|
||||
sistema podderzhivala fajly bol'shih razmerov. Bol'shie tablicy
|
||||
hranyatsya kak mnozhestvo fajlov razmerom v 1 GB, tak chto
|
||||
ogranicheniya, kotorye nakladyvaet fajlovaya sistema ne vazhny.
|
||||
|
||||
Maksimal'nyj razmer tablicy i maksimal'noe kolichestvo kolonok mogut
|
||||
byt' uvelicheny v chetyre raza, esli razmer bloka po umolchaniyu budet
|
||||
uvelichen do 32k.
|
||||
|
||||
Suschestvuet ogranichenie, po kotoromu indeksy ne mogut sozdavat'sya
|
||||
dlya kolonok dlinnee chem 2,000 simvolov. K schast'yu takie indeksy
|
||||
vryad li dejstvitel'no komu-to nuzhny. Unikal'nost' garantiruetsya
|
||||
nailuchim obrazom, s pomosch'yu funkcional'nogo indeksa iz h`esha MD5
|
||||
dlinnoj kolonki, a polnotekstovoe indeksirovanie pozvolyaet iskat'
|
||||
slova vnutri kolonki.
|
||||
|
||||
4.5) Kak mnogo diskovogo prostranstva v baze dannyh nuzhno dlya sohraneniya
|
||||
dannyh iz obychnogo tekstovogo fajla?
|
||||
|
||||
SUBD PostgreSQL mozhet potrebovat'sya diskovogo prostranstva do 5 raz
|
||||
bol'she dlya sohraneniya dannyh iz prostogo tekstovogo fajla.
|
||||
|
||||
V kachestve primera, rassmotrim fajl v 100,000 strok v kazhdoj, iz
|
||||
kotoryh celoe chislo i tekstovoe opisanie. Pri `etom dlina teksta, v
|
||||
srednem, sostavlyaet 20 bajt. Razmer prostogo fajla sostavit 2.8 MB.
|
||||
Razmer bazy PostgreSQL, soderzhaschej `eti zhe dannye sostavit
|
||||
priblizitel'no 5.2 MB iz kotoryh:
|
||||
24 bajt: na kazhdyj zagolovok stroki v tablice (priblizitel'no)
|
||||
+ 24 bajta: odno pole s celochislennym tipom i odno tekstovoe pole
|
||||
+ 4 bajta: ukazatel' na stranice dlya vsej tablichnoj stroki
|
||||
----------------------------------------
|
||||
56 bajt na stroku v tablice
|
||||
|
||||
Razmer stranicy dannyh v PostgreSQL sostavlyaet 8192 bajt (8 KB), tak chto:
|
||||
|
||||
8192 bajt na stranicu
|
||||
--------------------- = 158 strok v tablice na stranicu BD (okruglionno)
|
||||
52 bajt na stroku v tablice
|
||||
|
||||
100000 strok dannyh
|
||||
----------------------- = 633 stranic v BD (okruglionno)
|
||||
158 strok v tablice na stranicu
|
||||
|
||||
633 stranic BD * 8192 bajt na stranicu = 5,185,536 bajt (5.2 MB)
|
||||
|
||||
Indeksy ne trebuyut tak mnogo, no poskol'ku oni sozdayutsya dlya
|
||||
bol'shogo kolichestva dannyh, oni takzhe mogut byt' veliki.
|
||||
|
||||
Znacheniya NULL hranyatsya kak bitovye karty i po`etomu oni zanimayut
|
||||
ochen' malo mesta.
|
||||
|
||||
4.6) Pochemu moi zaprosy rabotayut medleno? Pochemu oni ne ispol'zuyut moi
|
||||
indeksy?
|
||||
|
||||
Indeksy ne ispol'zuyutsya dlya kazhdogo zaprosa. Oni ispol'zuyutsya
|
||||
tol'ko esli tablica bol'she minimal'nogo razmera i zapros vybiraet
|
||||
tol'ko malen'kij procent strok v tablice. Tak ustroeno, potomu chto
|
||||
dostup k disku s primeneniem randomizacii pri skanirovanii indeksov
|
||||
mozhet byt' medlennee, chem prostoe chtenie tablicy ili ee
|
||||
posledovatel'noe skanirovanie.
|
||||
|
||||
CHtoby opredelit' neobhodimost' ispol'zovaniya indeksa dlya kakoj-libo
|
||||
tablicy, PostgreSQL dolzhen imet' statistiku po `etoj tablice. `Eta
|
||||
statistika sobiraetsya pri ispol'zovanii VACUUM ANALYZE ili prosto
|
||||
ANALYZE. Ispol'zuya statistiku, optimizator uznaet o tom kak mnogo
|
||||
strok v tablice i esli on dolzhen ispol'zovat' indeksy, to on mozhet
|
||||
prinimat' luchshie resheniya. Statistika takzhe vliyaet na opredelenie
|
||||
optimal'nogo poryadka svyazyvaniya i metoda svyazyvaniya. Pri
|
||||
izmenenii soderzhimogo tablicy dolzhen periodicheski vypolnyatsya sbor
|
||||
statistiki.
|
||||
|
||||
Obychno indeksy ne ispol'zuyutsya dlya ORDER BY ili dlya vypolneniya
|
||||
svyazyvanij. Posledovatel'nyj perebor sleduyuschij za yavnoj
|
||||
sortirovkoj obychno bystree, chem poisk po indeksam v bol'shoj
|
||||
tablice. Odnako, ORDER BY chasto kombiniruetsya s LIMIT i v `etom
|
||||
sluchae indeks budet ispol'zovat'sya, poskol'ku pri vypolnenii budet
|
||||
vozvraschat'sya nebol'shaya chast' tablicy.
|
||||
|
||||
Esli vam kazhetsya, chto optimizator nekorrektno vybiraet
|
||||
posledovatel'nyj perebor, ispol'zujte SET enable_seqscan TO 'off' i
|
||||
zapustite zapros snova, chtoby uvidet', dejstvitel'no li skanirovanie
|
||||
indeksov bystree.
|
||||
|
||||
Kogda ispol'zuyutsya operacii s shablonami, naprimer LIKE ili ~,
|
||||
indeksy mogut byt' ispol'zovany v sleduyuschih sluchayah:
|
||||
* Nachalo stroki poiska dolzhno sovpadat' s nachalom iskomoj stroki,
|
||||
t.e.:
|
||||
+ LIKE shablony ne dolzhny nachinat'sya s %..
|
||||
+ ~ shablony regulyarnyh vyrazhenij dolzhna nachinat'sya na ^.
|
||||
* Stroka poiska ne dolzhna nachinat'sya s simvola klassa, t.e.
|
||||
[a-e].
|
||||
* Poisk nezavisimyj ot registra, takoj kak ILIKE i ~* ne ispol'zuet
|
||||
indeksy. Vmesto nego, ispol'zujte indeksy vyrazhenij, kotorye
|
||||
opisyvayutsya v sekcii 4.8.
|
||||
* Vo vremya initdb dolzhna ispol'zovat'sya lokal' po umolchaniyu C,
|
||||
potomu chto ne suschestvuet vozmozhnosti uznat' sleduyuschij
|
||||
naibol'shij simvol dlya ne-C lokali. Vy mozhete dlya takih
|
||||
sluchaev sozdat' special'nyj indeks text_pattern_ops kotoryj
|
||||
rabotaet tol'ko dlya LIKE indeksirovaniya. Dlya poiska slov takzhe
|
||||
mozhno ispol'zovat' polnotekstovyj indeks.
|
||||
|
||||
4.7) Kak posmotret' na to, kak optimizator vypolnyaet moj zapros?
|
||||
|
||||
Smotrite stranicu rukovodstva posvyaschennuyu EXPLAIN.
|
||||
|
||||
4.8) Kak mne vypolnit' poisk regulyarnogo vyrazheniya i poisk nezavisimyj ot
|
||||
registra bukv poisk regulyarnogo vyrazheniya? Kak mne ispol'zovat' indeks
|
||||
dlya poiska nezavisimogo ot registra bukv?
|
||||
|
||||
Operator ~ proizvodit poisk regulyarnogo vyrazheniya, a operator ~*
|
||||
proizvodit nezavisimyj ot registra bukv poisk regulyarnogo
|
||||
vyrazheniya. Nezavisimyj ot registra variant LIKE nazyvaetsya ILIKE.
|
||||
|
||||
Nezavisimoe ot registra sravnenie obychno vyrazhaetsya tak:
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
|
||||
`Eta konstrukciya ne budet ispol'zovat' standartnyj indeks. Odnako,
|
||||
esli vy sozdadite indeks vyrazheniya, on budet ispol'zovan:
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
|
||||
Esli vysheukazannyj indeks sozdaiotsya kak UNIQUE, to kolonka, dlya
|
||||
kotoroj on sozdaiotsya mozhet hranit' simvoly i v verhnem, i v nizhnem
|
||||
registre, indes ne mozhet imet' identichnyh znachenij, kotorye
|
||||
otlichayutsya tol'ko registrom. CHtoby v kolonke mozhno bylo hranit'
|
||||
simvoly tol'ko v opredelionnom registre, ispol'zujte ogranichenie
|
||||
CHECK ili proverku cherez trigger.
|
||||
|
||||
4.9) Kak mne opredelit', chto znachenie polya v kakom-libo zaprose ravno
|
||||
NULL? Kak mne soedinit' vozmozhnye NULL? Mogu ya sortirovat' polya NULL ili
|
||||
net?
|
||||
|
||||
Vy prosto sravnivaete znachenie s IS NULL i IS NOT NULL, kak zdes':
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
|
||||
CHtoby soedinit' s vozmozhnymi znacheniyami NULL, ispol'zujte
|
||||
COALESCE() kak zdes':
|
||||
SELECT COALESCE(col1, '') || COALESCE(col2, '')
|
||||
FROM tab
|
||||
|
||||
CHtoby otsortirovat' dannye po znacheniyu ispol'zujte modifikatory IS
|
||||
NULL i IS NOT NULL v vyrazhenii ORDER BY. Kogda oni budut generirovat'
|
||||
znacheniya istina, to pri sortirovke oni budut vyshe, chem znacheniya
|
||||
lozh', tak chto zapisi s NULL budut v otsortirovannom spiske sverhu:
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL);
|
||||
|
||||
4.10) Kakovy otlichiya mezhdu raznymi simvol'nymi tipami?
|
||||
|
||||
Tip Vnutrennee imya Zamechaniya
|
||||
VARCHAR(n) varchar razmer zadaet maksimal'nuyu dlinu, net zapolneniya
|
||||
CHAR(n) bpchar zapolnyaetsya pustotoj do fiksirovannoj dliny
|
||||
TEXT text net zadavaemogo verhnego ogranicheniya ili dliny
|
||||
BYTEA bytea massiv bajt peremennoj dliny (mozhno ispol'zovat'
|
||||
null-bajt bez opaski)
|
||||
"char" char odin simvol
|
||||
|
||||
Vnutrennee imya vy mozhete uvidet', kogda smotrite sistemnye katalogi
|
||||
i v nekotoryh soobscheniyah ob oshibkah.
|
||||
|
||||
Pervye chetyre tipa yavlyayutsya "varlena" tipami (t.e., pervye
|
||||
chetyre bajta na diske yavlyayutsya dlinnoj, za kotoroj sleduyut
|
||||
dannye). Takim obrazom, fakticheski ispol'zuemoe prostranstvo bol'she,
|
||||
chem oboznachennyj razmer. Odnako, dlinnye znacheniya takzhe
|
||||
szhimayutsya, tak chto zanimaemoe diskovoe prostranstvo mozhet takzhe
|
||||
byt' i men'she, chem ozhidalos'.
|
||||
VARCHAR(n) - `eto luchshee reshenie, kogda nuzhno hranit' stroki
|
||||
peremennoj dliny, ne prevyshayuschie opredelennogo razmera. TEXT -
|
||||
`eto luchshee reshenie dlya strok neogranichennoj dliny, s maksimal'no
|
||||
dopustimoj dlinoj v 1 gigabajt.
|
||||
|
||||
CHAR(n) - `eto luchshee reshenie dlya hraneniya strok, kotorye obychno
|
||||
imeyut odinakovuyu dlinu. CHAR(n) zapolnyaetsya pustotoj do zadannoj
|
||||
dliny, v to vremya kak VARCHAR(n) hranit tol'ko simvoly, iz kotoryh
|
||||
sostoit stroka. BYTEA ispol'zuetsya dlya hraneniya binarnyh dannyh,
|
||||
znacheniya kotoryh mogut vklyuchat' NULL bajty. Vse tipy opisannye
|
||||
zdes', imeyut shodnye harakteristiki proizvoditel'nosti.
|
||||
|
||||
4.11.1) Kak mne sozdat' pole serial/s-avto-uvelicheniem?
|
||||
|
||||
PostgreSQL podderzhivaet tip dannyh SERIAL. On avtomaticheski sozdaet
|
||||
posledovatel'nost'. Naprimer:
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
);
|
||||
|
||||
avtomaticheski transliruetsya v:
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
|
||||
Avtomaticheski sozdannaya posledovatel'nost' imeet imya vida
|
||||
<tablica>_<kolonka_serial>_seq, gde tablica i kolonka_serial - `eto
|
||||
sootvetstvenno imena tablicy i kolonki s tipom SERIAL. Smotrite
|
||||
podrobnosti o posledovatel'nostyah na stranice rukovodstva
|
||||
posvyaschennoj create_sequence.
|
||||
|
||||
4.11.2) Kak mne poluchit' znachenie pri vstavke SERIAL?
|
||||
|
||||
Prostejshij sposob poluchit' naznachennoe znachenie SERIAL `eto
|
||||
ispol'zovat' RETURNING. Ispol'zuya dlya primera tablicu v 4.11.1, `eto
|
||||
mozhet vyglyadet' tak:
|
||||
INSERT INTO person (name) VALUES ('Blaise Pascal') RETURNING id;
|
||||
|
||||
Vy takzhe mozhete vyzvat' nextval() i ispol'zovat' `eto znachenie v
|
||||
INSERT ili vyzvat' currval() posle INSERT.
|
||||
|
||||
4.11.3) Ne mozhet li poluchit'sya tak, chto ispol'zovanie currval() i
|
||||
nextval() privedet k zaciklirovaniyu s drugimi pol'zovatelyami?
|
||||
|
||||
Net. currval() vozvraschaet tekuschee znachenie, naznachennoe vashej
|
||||
sessiej, a ne drugimi sessiyami.
|
||||
|
||||
4.11.4) Pochemu chisla iz moej posledovatel'nosti ne ispol'zuyutsya snova pri
|
||||
otmene tranzakcii? Pochemu sozdayutsya razryvy pri numeracii v kolonke, gde
|
||||
ya ispol'zuyu posledovatel'nost'/SERIAL?
|
||||
|
||||
Dlya realizacii konkuretnosti, znacheniya posledovatel'nostej, pri
|
||||
neobhodimosti vydayutsya vo vremya zapuska tranzakcij i ne
|
||||
blokiruyutsya do polnogo vypolneniya tranzakcij. `Eto mozhet vyzyvat'
|
||||
razryvy v numeracii pri otmene tranzakcij.
|
||||
|
||||
4.12) CHto takoe OID? CHto takoe CTID?
|
||||
|
||||
Esli tablica sozdana s WITH OIDS, to kazhdaya stroka poluchaet
|
||||
unikal'nyj indentifikator OID. OID - `eto avtomaticheski naznachaemoe
|
||||
unikal'noe 4-h bajtovoe celoe chislo, kotoroe unikal'no dlya vsej
|
||||
ustanovlennoj SUBD. Odnako, posle togo kak ego znachenie prevysit 4
|
||||
milliarda, znacheniya OID nachinayut dublirovat'sya. PostgreSQL
|
||||
ispol'zuet OID dlya svyazyvaniya svoih vnutrennih tablic.
|
||||
|
||||
Dlya unikal'nogo znacheniya v strokah tablicy pol'zovatelya, luchshim
|
||||
sposobom yavlyaetsya ispol'zovanie SERIAL vmesto OID, potomu chto
|
||||
posledovatel'nosti SERIAL unikal'ny tol'ko vnutri tablicy i takim
|
||||
obrazom men'she podverzheny perepolneniyu. Dlya hraneniya znachenij
|
||||
8-mi bajtnoj posledovatel'nosti dostupen tip SERIAL8.
|
||||
|
||||
CTID ispol'zuetsya dlya identifikacii special'nyh fizicheskih zapisej
|
||||
s blochnymi i offset znacheniyami. CTID izmenyaetsya posle togo kak
|
||||
stroki v tablice byli izmeneny ili peregruzheny.
|
||||
|
||||
TID ispol'zuetsya indeksnymi zapisyami v kachestve ukazatelya na
|
||||
fizicheskie zapisi.
|
||||
|
||||
4.13) Pochemu ya poluchayu oshibku "ERROR: Memory exhausted in
|
||||
AllocSetAlloc()"?
|
||||
|
||||
Predpolozhitel'no u vas zakonchilas' virtual'naya pamyat' ili chto
|
||||
vashe yadro imeet malen'kij limit na opredelennye resursy. Popytajtes'
|
||||
pered zapuskom servera BD vypolnit' sleduyuschie komandy:
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
|
||||
V zavisimosti ot komandnogo interpretatora shell, tol'ko odna iz
|
||||
dannyh komand vypolnitsya uspeshno, no ona pozvolit vam ustanovit'
|
||||
bol'shij segment dannyh processa i vozmozhno reshit problemu. `Eta
|
||||
komanda izmenyaet parametry tekuschego processa i vseh ego potomkov,
|
||||
sozdannyh posle eio zapuska. Esli u vas voznikla problema s SQL
|
||||
klientom, potomu chto backend vozvraschaet slishkom bol'shoj ob"em
|
||||
dannyh, popytajtes' vypolnit' `etu komandu pered zapuskom klienta.
|
||||
|
||||
4.14) Kak mne uznat', kakaya versiya PostgreSQL zapuschena?
|
||||
|
||||
Iz psql, naberite SELECT version();
|
||||
|
||||
4.15) Kak mne sozdat' kolonku kotoraya po umolchaniyu budet soderzhat'
|
||||
tekuschee vremya?
|
||||
|
||||
Ispol'zujte CURRENT_TIMESTAMP:
|
||||
CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
|
||||
4.16) Kak mne vypolnit' vneshnee svyazyvanie?
|
||||
|
||||
PostgreSQL podderzhivaet vneshnee svyazyvanie, ispol'zuya standartnyj
|
||||
sintaksis SQL. Vot dva primera:
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
|
||||
ili
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
|
||||
`Eto identichnye zaprosy svyazyvaniya t1.col i t2.col, takzhe
|
||||
vozvraschayut lyubye nesvyazannye stroki v t1 (kotorye ne sovpadayut s
|
||||
t2). RIGHT svyazyvanie dolzhno dobavit' nesvyazannye stroki t2. FULL
|
||||
svyazyvanie dolzhno vozvratit' sovpavshie stroki plyus vse
|
||||
nesvyazannye stroki iz t1 i t2. Slovo OUTER yavlyaetsya
|
||||
neobyazatel'nym i naznachaetsya v LEFT, RIGHT i FULL svyazyvaniyah.
|
||||
Obychnye svyazyvaniya nazyvayutsya INNER svyazyvaniya.
|
||||
|
||||
4.17) Kak vypolnyat' zaprosy, ispol'zuyuschie neskol'ko baz dannyh?
|
||||
|
||||
Ne suschestvuet sposoba sozdat' zapros k bazam dannyh otlichnym ot
|
||||
tekuschej. Poskol'ku PostgreSQL zagruzhaet sistemnye katalogi
|
||||
specifichnye dlya bazy dannyh, neponyatno dazhe, kak dolzhen sebya
|
||||
vesti takoj mezhbazovyj zapros.
|
||||
|
||||
contrib/dblink pozvolyaet zaprosy mezhdu bazami, ispol'zuya vyzovy
|
||||
funkcij. Razumeetsya, klient mozhet odnovremenno takzhe ustanavlivat'
|
||||
soedieneniya s razlichnymi bazami dannyh i takih obrazom ob"edinyat'
|
||||
informaciyu iz nih.
|
||||
|
||||
4.18) Kak mne vernut' iz funkcii neskol'ko strok tablicy?
|
||||
|
||||
Vy mozhete legko ispol'zovat' funkcii, vozvraschayuschie spisok,
|
||||
http://wiki.postgresql.org/wiki/Return_more_than_one_row_of_data_from_
|
||||
PL/pgSQL_functions.
|
||||
|
||||
4.19) Pochemu ya poluchayu oshibku "relation with OID #### ne suschestvuet",
|
||||
kogda obraschayuts' k vremennym tablicam v funkciyah PL/PgSQL?
|
||||
|
||||
V PostgreSQL do versii 8.3, PL/PgSQL k`eshiruet scenarii funkcii i
|
||||
odin iz negativnyh `effektov `etogo sostoit v tom, chto esli funkciya
|
||||
PL/PgSQL obraschaetsya k vremennoj tablice i `eta tablica pozdnee
|
||||
udalyaetsya i peresozdaetsya, a funkciya zatem vyzyvaetsya snova, to
|
||||
ee vyzov privedet k oshibke, potomu chto sk`eshirovannoe soderzhimoe
|
||||
funkcii soderzhit ukazatel' na staruyu vremennuyu tablicu. CHtoby
|
||||
reshit' `etu problemu, ispol'zujte EXECUTE dlya dostupa k vremennym
|
||||
tablicam v PL/PgSQL. Ispol'zovanie `etogo operatora zastavit zapros
|
||||
peregenerirovat'sya kazhdyj raz.
|
||||
|
||||
V PostgreSQL 8.3 i pozdnee, `etoj problemy net.
|
||||
|
||||
4.20) Kakie est' resheniya dlya replikacii?
|
||||
|
||||
Hotya "replikaciya" -- `eto edinyj termin, est' neskol'ko raznyh
|
||||
tehnologij dlya vypolneniya replikacij s raznymi osobennostyami dlya
|
||||
kazhdoj.
|
||||
|
||||
Replikaciya Master/slave pozvolyaet imet' odin glavnyj (master) server
|
||||
dlya vypolneniya zaprosov chteniya/zapisi, v to vremya kak
|
||||
podchinionnye (slave) servera mogut proizvodit' tol'ko zaprosy
|
||||
chteniya/SELECT. Naibolee populyarnym resheniem dlya replikacii
|
||||
master-slave v PostgreSQL yavlyaetsya Slony-I.
|
||||
|
||||
Replikaciya Multi-master pozvolyaet vypolnyat' zaprosy chteniya/zapisi
|
||||
na neskol'kih, repliciruemyh drug s drugom komp'yuetrah. `Eta
|
||||
osobennost' takzhe privodit k potere proizvoditel'nosti, potomu chto
|
||||
neobhodima sinhronizaciya izmenenij mezhdu neskol'kimi serverami.
|
||||
Naibolee populyarnym resheniem dlya takoj replikacii v PostgreSQL
|
||||
yavlyaetsya PGcluster.
|
||||
|
||||
4.21) Pochemu imena tablicy i kolonok ne raspoznayutsya v v moiom zaprose?
|
||||
Pochemu ne sohranyayutsya zaglavnye bukvy?
|
||||
|
||||
Naibolee chasto imena neraspoznayutsya iz-za ispol'zovaniya dvojnyh
|
||||
kavychek v imeni tablicy ili kolonki pri sozdanii tablicy. Pri
|
||||
ispol'zovanii dvojnyh kavychek, imya tablicy i kolonki (kotorye
|
||||
nazyvayut identifikatorami) sohranyayutsya v registro-zavisimom vide;
|
||||
`eto oznachaet, chto vy dolzhny ispol'zovat' dvojnye kavychki, kogda
|
||||
ukazyvaete `eti imena v zaprose. Nekotorye interfejsy, takie kak
|
||||
pgAdmin, vo vremya sozdaniya tablicy dobavlyayut dvojnye kavychki
|
||||
avtomaticheski. Takim obrazom, chtoby identifikatory raspoznavalis' vy
|
||||
dolzhny sledovat' odnomu iz sleduyuschih pravil:
|
||||
* Izbegat' ispol'zovaniya dvojnyh kavychek pri sozdanii tablic
|
||||
* Ispol'zovat' v identifikatorah tol'ko simvoly nizhnego registra
|
||||
* Ispol'zovat' dvojnye kavychki dlya identifikatorov v zaprosah
|
||||
1192
doc/FAQ_turkish
1192
doc/FAQ_turkish
File diff suppressed because it is too large
Load Diff
@ -1,82 +0,0 @@
|
||||
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||||
<html>
|
||||
<head>
|
||||
<meta http-equiv="content-type"
|
||||
content="text/html; charset=ISO-8859-1">
|
||||
<title>PostgreSQL Native Win32 Status Report</title>
|
||||
</head>
|
||||
<body>
|
||||
<h1 style="text-align: center;">Compiling PostgreSQL On Native Win32 FAQ<br>
|
||||
</h1>
|
||||
<P>Last updated: Thu Oct 14 18:22:57 EDT 2004</P>
|
||||
<P>Current maintainer: Bruce Momjian <<A href=
|
||||
"mailto:bruce@momjian.us">bruce@momjian.us</A>><BR>
|
||||
</P>
|
||||
|
||||
<P>The most recent version of this document can be viewed at <A href=
|
||||
"http://www.postgresql.org/docs/faqs.FAQ_MINGW.html">
|
||||
http://www.postgresql.org/docs/faqs.FAQ_MINGW.html</A>.</P>
|
||||
|
||||
<P>The FAQ Running & Installing PostgreSQL On Native Windows is at <A href=
|
||||
"http://pginstaller.projects.postgresql.org/faq/FAQ_windows.html">
|
||||
http://pginstaller.projects.postgresql.org/faq/FAQ_windows.html</A>.</P>
|
||||
|
||||
<p>The native Win32 port is built from source using MinGW tools.
|
||||
There is also a precompiled binary installer called <span
|
||||
style="font-style: italic;">pginstaller</span> which you can find at
|
||||
from <a href="http://pgfoundry.org/projects/pginstaller">http://pgfoundry.org/projects/pginstaller</a>.
|
||||
It is a fully native build and uses no additional software like MinGW.
|
||||
The ready-made installer files are available on the main PostgreSQL ftp servers
|
||||
in the binary/win32 directory.
|
||||
<br>
|
||||
</p>
|
||||
<h2>Tools for Building Binaries<br>
|
||||
</h2>
|
||||
<p> The native Win32 port requires a 32-bit NT-based Microsoft
|
||||
operating
|
||||
system, like Windows NT 4, Windows 2000/2003, or Windows XP. (NT 4
|
||||
is no longer supported since version 8.2) Earlier
|
||||
operating systems do not have sufficient infrastructure. Building the
|
||||
port also
|
||||
requires MinGW and Msys, which can be downloaded from <a
|
||||
href="http://www.mingw.org/">http://www.mingw.org/</a>. MinGW is
|
||||
a Unix-like build environment for Microsoft operating systems.
|
||||
Msys is a collection of unix tools required to run shell scripts like <i>configure.
|
||||
</i>Neither is required to run the resulting binaries; they are
|
||||
needed only for creating the binaries. Work is in progress to support
|
||||
building using Visual C++ in a future version.<br>
|
||||
</p>
|
||||
<h2>Steps For Building Binaries<br>
|
||||
</h2>
|
||||
<ul>
|
||||
<li>Download the nightly snapshot tarball from <a
|
||||
href="ftp://ftp.postgresql.org/pub/dev">ftp://ftp.postgresql.org/pub/dev</a>
|
||||
or checkout via CVS (you will need <i>bison, flex,</i> and <i>perl</i>
|
||||
installed to build from CVS)<br>
|
||||
</li>
|
||||
<li>Run <i>configure</i> (you might need to add the --without-zlib
|
||||
argument, depending on whether you have installed <span
|
||||
style="font-style: italic;">zlib
|
||||
</span>on MinGW)</li>
|
||||
<li>Run <i>make install</i></li>
|
||||
</ul>
|
||||
Note: it is suggested that you run <i>psql</i> under <i>CMD.EXE.</i>,
|
||||
as the Msys console has buffering issues.<br>
|
||||
<br>
|
||||
If you make a change that you want to contribute, make a context diff
|
||||
and send
|
||||
it to the mailing list. <br>
|
||||
<h2>Resources</h2>
|
||||
There are several resources that helped us complete this port:<br>
|
||||
<ul>
|
||||
<li>PeerDirect port of PostgreSQL 7.2 to Win32 (<a
|
||||
href="ftp://momjian.postgresql.org/pub/postgresql/win32/PeerDirect">ftp://momjian.postgresql.org/pub/postgresql/win32/PeerDirect</a>)</li>
|
||||
<li>CONNX Win32 signal code(<a
|
||||
href="ftp://momjian.postgresql.org/pub/postgresql/win32/CONNX">ftp://momjian.postgresql.org/pub/postgresql/win32/CONNX</a>)</li>
|
||||
<li>SRA port of PostgreSQL to Win32 (unfortunately, this is not
|
||||
publically available because the threaded portion is proprietary)</li>
|
||||
<li>CHM help files (<a
|
||||
href="http://www.pgadmin.org/snapshots/help/en_US/pgadmin3.chm">http://www.pgadmin.org/snapshots/help/en_US/pgadmin3.chm</a>)</li>
|
||||
</ul>
|
||||
</body>
|
||||
</html>
|
||||
@ -1,942 +0,0 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||||
<HTML>
|
||||
<HEAD>
|
||||
<META name="generator" content="HTML Tidy, see www.w3.org">
|
||||
<META http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||||
<TITLE>FAQ do PostgreSQL</TITLE>
|
||||
</HEAD>
|
||||
|
||||
<BODY bgcolor="#ffffff" text="#000000" link="#ff0000" vlink="#a00000"
|
||||
alink="#0000ff">
|
||||
<H1>Perguntas Frequentes (FAQ) sobre PostgreSQL</H1>
|
||||
|
||||
<P>Última atualização: Sex Nov 16 10:53:50 EST 2007</P>
|
||||
|
||||
<P>Mantenedor atual: Bruce Momjian (<A href=
|
||||
"mailto:bruce@momjian.us">bruce@momjian.us</A>)
|
||||
</P>
|
||||
|
||||
<P>Traduzido por: Euler Taveira de Oliveira (<A href=
|
||||
"mailto:euler@timbira.com">euler@timbira.com</A>)</P>
|
||||
|
||||
<P>A versão mais recente desse documento pode ser vista em <A href=
|
||||
"http://www.postgresql.org/files/documentation/faqs/FAQ.html">
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ.html</A> (EN).<BR>
|
||||
<A href="http://www.postgresql.org/files/documentation/faqs/FAQ_brazilian.html">
|
||||
http://www.postgresql.org/files/documentation/faqs/FAQ_brazilian.html</A> (pt_BR).</P>
|
||||
|
||||
<P>Perguntas sobre plataformas específicas são respondidas em <A href=
|
||||
"http://www.postgresql.org/docs/faq/">http://www.postgresql.org/docs/faq/</A>.</P>
|
||||
<HR>
|
||||
|
||||
<H2 align="center">Perguntas Gerais</H2>
|
||||
<A href="#item1.1">1.1</A>) O que é PostgreSQL? Como ele é pronunciado?
|
||||
O que é Postgres?<BR>
|
||||
<A href="#item1.2">1.2</A>) Quem controla o PostgreSQL?<BR>
|
||||
<A href="#item1.3">1.3</A>) Qual é a licença do PostgreSQL?<BR>
|
||||
<A href="#item1.4">1.4</A>) Quais plataformas o PostgreSQL pode ser executado?<BR>
|
||||
<A href="#item1.5">1.5</A>) Onde eu posso conseguir o PostgreSQL?<BR>
|
||||
<A href="#item1.6">1.6</A>) Qual é a última versão?<BR>
|
||||
<A href="#item1.7">1.7</A>) Onde eu posso conseguir suporte?<BR>
|
||||
<A href="#item1.8">1.8</A>) Como eu posso submeter um relato de um bug?<BR>
|
||||
<A href="#item1.9">1.9</A>) Como eu posso saber quais são os bugs conhecidos ou características ausentes?<BR>
|
||||
<A href="#item1.10">1.10</A>) Que documentação está disponível?<BR>
|
||||
<A href="#item1.11">1.11</A>) Como eu posso aprender <SMALL>SQL</SMALL>?<BR>
|
||||
<A href="#item1.12">1.12</A>) Como posso submeter uma correção (patch) ou me juntar a equipe de desenvolvimento?<BR>
|
||||
<A href="#item1.13">1.13</A>) Como é o PostgreSQL comparado a outros <SMALL>SGBD</SMALL>s?<BR>
|
||||
<A href="#item1.14">1.14</A>) O PostgreSQL gerenciar<61> as mudanças de horário devido ao horário de verão em vários países?<BR>
|
||||
|
||||
|
||||
<H2 align="center">Perguntas sobre Clientes</H2>
|
||||
<A href="#item2.1">2.1</A>) Quais interfaces estão disponíveis para PostgreSQL?<BR>
|
||||
<A href="#item2.2">2.2</A>) Quais ferramentas estão disponíveis para utilizar o PostgreSQL com páginas Web?<BR>
|
||||
<A href="#item2.3">2.3</A>) O PostgreSQL tem interfaces gráficas para interagir com usuário?<BR>
|
||||
|
||||
|
||||
<H2 align="center">Perguntas Administrativas</H2>
|
||||
<A href="#item3.1">3.1</A>) Como eu instalo o PostgreSQL em um local diferente de <I>/usr/local/pgsql</I>?<BR>
|
||||
<A href="#item3.2">3.2</A>) Como eu controlo conexões de outras máquinas?<BR>
|
||||
<A href="#item3.3">3.3</A>) Como eu ajusto o servidor de banco de dados para obter uma performance melhor?<BR>
|
||||
<A href="#item3.4">3.4</A>) Quais características de depuração estão disponíveis?<BR>
|
||||
<A href="#item3.5">3.5</A>) Por que eu recebo <I>"Sorry, too many clients"</I> quando eu tento conectar?<BR>
|
||||
<A href="#item3.6">3.6</A>) Qual é o processo de atualização do PostgreSQL?<BR>
|
||||
<A href="#item3.7">3.7</A>) Que tipo de hardware eu devo usar?<BR>
|
||||
|
||||
|
||||
<H2 align="center">Perguntas Operacionais</H2>
|
||||
<A href="#item4.1">4.1</A>) Como eu faço um <SMALL>SELECT</SMALL> somente dos primeiros registros de uma consulta? Um registro randômico?<BR>
|
||||
<A href="#item4.2">4.2</A>) Como eu descubro quais tabelas, índices, bancos de dados e usuários estão definidos? Como eu vejo as consultas utilizadas pelo <I>psql</I> para mostrá-los?<BR>
|
||||
<A href="#item4.3">4.3</A>) Como você muda o tipo de dado de uma coluna?<BR>
|
||||
<A href="#item4.4">4.4</A>) Qual é o tamanho máximo de um registro, uma tabela e um banco de dados?<BR>
|
||||
<A href="#item4.5">4.5</A>) Quanto espaço em disco é necessário para armazenar dados de um arquivo texto?<BR>
|
||||
<A href="#item4.6">4.6</A>) Por que minhas consultas estão lentas? Por que elas não estão utilizando meus índices?<BR>
|
||||
<A href="#item4.7">4.7</A>) Como eu vejo como o otimizador de consultas está avaliando minha consulta?<BR>
|
||||
<A href="#item4.8">4.8</A>) Como eu faço buscas com expressões regulares e buscas com expressões regulares sem diferenciar mauúsculas de minúsculas? Como eu utilizo um índice para buscas sem distinguir maiúsculas de minúsculas?<BR>
|
||||
<A href="#item4.9">4.9</A>) Em uma consulta, como eu detecto se um campo é <SMALL>NULL</SMALL>? Como eu posso concatenar possíveis <SMALL>NULL</SMALL>s? Como eu posso ordenar por um campo que é <SMALL>NULL</SMALL> ou não?<BR>
|
||||
<A href="#item4.10">4.10</A>) Qual é a diferença entre os vários tipos de dado de caracteres?<BR>
|
||||
<A href="#item4.11.1">4.11.1</A>) Como eu crio um campo serial/auto incremento?<BR>
|
||||
<A href="#item4.11.2">4.11.2</A>) Como eu consigo o valor de um campo
|
||||
<SMALL>SERIAL</SMALL>?<BR>
|
||||
<A href="#item4.11.3">4.11.3</A>) <I>currval()</I> não lida com condição de corrida com outros usuários?<BR>
|
||||
<A href="#item4.11.4">4.11.4</A>) Por que os números da minha sequência não são reutilizados quando uma transação é abortada? Por que há intervalos nos números da minha sequência/coluna SERIAL?<BR>
|
||||
<A href="#item4.12">4.12</A>) O que é um <SMALL>OID</SMALL>? O que é um <SMALL>CTID</SMALL>?<BR>
|
||||
<A href="#item4.13">4.13</A>) Por que eu recebo o erro <I>"ERROR: Memory exhausted in AllocSetAlloc()"</I>?<BR>
|
||||
<A href="#item4.14">4.14</A>) Como eu informo qual versão do PostgreSQL eu estou utilizando?<BR>
|
||||
<A href="#item4.15">4.15</A>) Como eu crio uma coluna que conterá por padrão a hora atual?<BR>
|
||||
<A href="#item4.16">4.16</A>) Como eu faço uma junção externa (outer join)?<BR>
|
||||
<A href="#item4.17">4.17</A>) Como eu faço consultas utilizando múltiplos bancos de dados?<BR>
|
||||
<A href="#item4.18">4.18</A>) Como eu retorno múltiplos registros ou colunas de uma função?<BR>
|
||||
<A href="#item4.19">4.19</A>) Por que eu obtenho erros "relation with OID ######
|
||||
does not exist" ao acessar tabelas temporárias em funções PL/PgSQL?<BR>
|
||||
<A href="#item4.20">4.20</A>) Quais soluções de replicação estão disponíveis?<BR>
|
||||
<A href="#item4.21">4.21</A>) Por que os nomes de minhas tabelas e colunas não
|
||||
são reconhecidos em minha consulta? Por que as maiúsculas não são preservadas?<BR>
|
||||
|
||||
|
||||
<HR>
|
||||
|
||||
<H2 align="center">Perguntas Gerais</H2>
|
||||
|
||||
<H3 id="item1.1">1.1) O que é PostgreSQL? Como ele é pronunciado? O que é Postgres?</H3>
|
||||
|
||||
<P>PostgreSQL é pronunciado <I>Post-Gres-Q-L</I>.
|
||||
(Para os curiosos que querem saber como se diz "PostgreSQL", um
|
||||
<a href="http://www.postgresql.org/files/postgresql.mp3">arquivo de áudio</a> está disponível).</P>
|
||||
|
||||
<P>O PostgreSQL é um sistema de banco de dados objeto-relacional que tem as
|
||||
características de sistemas de bancos de dados comerciais tradicionais com
|
||||
melhoramentos encontrados nos sistemas <SMALL>SGBD</SMALL>s de próxima geração.
|
||||
PostgreSQL é livre e o código-fonte completo está disponível.</P>
|
||||
|
||||
<P>O desenvolvimento do PostgreSQL é feito por um grupo de desenvolvedores
|
||||
voluntários (na sua maioria) espalhados pelo mundo e que se comunicam via
|
||||
Internet. É um projeto da comunidade e não é controlado por nenhuma
|
||||
empresa. Para se envolver, veja a FAQ do desenvolvedor em <A href=
|
||||
"http://www.postgresql.org/docs/faqs.FAQ_DEV.html">
|
||||
http://www.postgresql.org/docs/faqs.FAQ_DEV.html</A>
|
||||
</P>
|
||||
|
||||
<P>Postgres é um apelido para o PostgreSQL amplamente utilizado. Era o nome original do
|
||||
projeto em Berkeley e dentre os outros apelidos é o preferido. Se você acha
|
||||
'PostgreSQL' difícil de pronunciar, diga apenas 'Postgres'.</P>
|
||||
|
||||
<H3 id="item1.2">1.2) Quem controla o PostgreSQL?<BR></H3>
|
||||
|
||||
<P>Se você está procurando por um mantenedor, comitê central ou empresa
|
||||
controladora do PostgreSQL, desista --- não há um(a). Nós temos um
|
||||
comitê core e committers CVS, mas estes grupos são mais para questões
|
||||
administrativas do que controle. O projeto é direcionado pela comunidade
|
||||
de desenvolvedores e usuários, que qualquer um pode se juntar. Tudo o que
|
||||
você precisa é se inscrever nas listas de discussão e participar das
|
||||
discussões. Veja a <a href="http://www.postgresql.org/docs/faqs.FAQ_DEV.html">
|
||||
FAQ do desenvolvedor</A> para obter informações como se envolver com o
|
||||
desenvolvimento do PostgreSQL.</P>
|
||||
|
||||
<H3 id="item1.3">1.3) Qual é a licença do PostgreSQL?</H3>
|
||||
|
||||
<P>O PostgreSQL é distribuído sob a licença BSD clássica. Basicamente,
|
||||
ela permite que usuários façam qualquer coisa com o código, incluindo
|
||||
revender os binários sem o código-fonte. A única restrição é que você
|
||||
não nos responsabilize legalmente por problemas com o programa de computador.
|
||||
Há também a exigência de que esta licença apareça em todas as cópias
|
||||
do programa de computador. Aqui está a licença BSD que usamos atualmente:</P>
|
||||
<P>PostgreSQL está sujeito a seguinte licença:</P>
|
||||
|
||||
<P>PostgreSQL Data Base Management System</P>
|
||||
|
||||
<P>Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
|
||||
Portions Copyright (c) 1994-1996 Regents of the University of California</P>
|
||||
|
||||
<P>Permission to use, copy, modify, and distribute this software
|
||||
and its documentation for any purpose, without fee, and without a
|
||||
written agreement is hereby granted, provided that the above
|
||||
copyright notice and this paragraph and the following two
|
||||
paragraphs appear in all copies.</P>
|
||||
|
||||
<P>IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY
|
||||
PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
|
||||
DAMAGES, INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS
|
||||
SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
|
||||
CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</P>
|
||||
|
||||
<P>THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
|
||||
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
||||
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
|
||||
SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE
|
||||
UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
|
||||
SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.</P>
|
||||
|
||||
<H3 id="item1.4">1.4) Quais plataformas o PostgreSQL pode ser executado?</H3>
|
||||
|
||||
<P>Em geral, qualquer plataforma moderna compatível com Unix deve ser capaz de executar o PostgreSQL. As plataformas que foram testadas antes do lançamento de uma versão são listadas nas instruções de instalação.</P>
|
||||
|
||||
<P>O PostgreSQL também executa nativamente nos sistemas operacionais Microsoft Windows
|
||||
baseados no NT tais como Win200 SP4, WinXP e Win2003. Um instalador pré-empacotado está
|
||||
disponível em <a href= "http://pgfoundry.org/projects/pginstaller">
|
||||
http://pgfoundry.org/projects/pginstaller</a>. Versões do Windows baseadas no MS-DOS
|
||||
(Win95, Win98, WinMe) podem executar o PostgreSQL utilizando o Cygwin.</P>
|
||||
|
||||
<p>Há também uma versão para o Novell Netware 6 em
|
||||
<a href="http://forge.novell.com">http://forge.novell.com</a>
|
||||
e uma versão para OS/2 (eComStation) em <a href=
|
||||
"http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgreSQL&stype=all&sort=type&dir=%2F">
|
||||
http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgreSQL&stype=all&sort=type&dir=%2F</a>.</p>
|
||||
|
||||
<H3 id="item1.5">1.5) Onde eu posso conseguir o PostgreSQL?</H3>
|
||||
|
||||
<P>Via navegador web, utilize <a href="http://www.postgresql.org/ftp/">
|
||||
http://www.postgresql.org/ftp/</a> e via ftp, utilize
|
||||
<A href="ftp://ftp.postgresql.org/pub/">
|
||||
ftp://ftp.postgresql.org/pub/</A>.</P>
|
||||
|
||||
|
||||
<H3 id="item1.6">1.6) Qual é a última versão?</H3>
|
||||
|
||||
<P>A última versão do PostgreSQL é a versão 8.2.5.</P>
|
||||
|
||||
<P>Nós planejamos lançar versões novas a cada ano com versões
|
||||
corretivas em alguns meses.</P>
|
||||
|
||||
<H3 id="item1.7">1.7) Onde eu posso conseguir suporte?</H3>
|
||||
|
||||
<P>A comunidade do PostgreSQL fornece assistência a muitos de seus
|
||||
usuários via e-mail. O principal sítio web para inscrição nas listas
|
||||
de e-mail é <a href="http://www.postgresql.org/community/lists/">
|
||||
http://www.postgresql.org/community/lists/</a>. As listas <I>general</I>
|
||||
e <I>bugs</I> são um bom lugar para início.</P>
|
||||
|
||||
<P>O principal canal de IRC é o <I>#postgresql</I> na Freenode (<I>irc.freenode.net</I>). Para se conectar você pode utilizar o comando Unix <code>irc -c '#postgresql' "$USER" irc.freenode.net</code> ou utilizar qualquer outro cliente de IRC. Um canal hispânico (<I>#postgresql-es</I>) e um francês (<I>#postgresqlfr</I>) também existem na mesma rede. Há também um canal PostgreSQL na EFNet.</P>
|
||||
|
||||
<P>Uma lista de empresas que prestam suporte comercial está disponível em <A href=
|
||||
"http://www.postgresql.org/support/professional_support">
|
||||
http://www.postgresql.org/support/professional_support</A>.</P>
|
||||
|
||||
<H3 id="item1.8">1.8) Como eu informo a existência de um bug?</H3>
|
||||
|
||||
<P>Visite o formulário que reporta bugs do PostgreSQL em <A href=
|
||||
"http://www.postgresql.org/support/submitbug">http://www.postgresql.org/support/submitbug</A>.</P>
|
||||
<P>Verifique também o nosso ftp <A href=
|
||||
"ftp://ftp.postgresql.org/pub">ftp://ftp.postgresql.org/pub</A> para
|
||||
ver se há uma versão mais recente do PostgreSQL.</P>
|
||||
|
||||
<P>Bugs submetidos utilizando o formulário ou informado a qualquer
|
||||
lista de discussão do PostgreSQL tipicamente gera uma das seguintes
|
||||
respostas:</P>
|
||||
<ul>
|
||||
<li>Não é um bug e o porquê</li>
|
||||
<li>É um bug conhecido e já está na lista de
|
||||
<A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A></li>
|
||||
<li>O bug foi corrigido na versão atual</li>
|
||||
<li>O bug foi corrigido mas não foi empacotado em um versão oficial</li>
|
||||
<li>Um pedido foi feito para obter informações detalhadas:
|
||||
<ul>
|
||||
<li>Sistema Operacional</li>
|
||||
<li>Versão do PostgreSQL</li>
|
||||
<li>Exemplo de teste que reproduz o bug</li>
|
||||
<li>Informações sobre depuração</li>
|
||||
<li>Saída reconstituidora de vestígios (backtrace) do depurador</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li>O bug é novo. O seguinte pode ocorrer:
|
||||
<ul>
|
||||
<li>Uma correção é criada e será incluída na próxima versão</li>
|
||||
<li>O bug não pode ser corrigido imediatamente e é adicionado
|
||||
a lista de <A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A></li>
|
||||
</ul>
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
<H3 id="item1.9">1.9) Como eu posso saber quais são os bugs conhecidos
|
||||
ou funcionalidades ausentes?</H3>
|
||||
|
||||
<P>O PostgreSQL suporta um subconjunto extendido do <SMALL>SQL:2003</SMALL>.
|
||||
Veja nossa lista de <A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A>
|
||||
que contém bugs conhecidos, funcionalidades ausentes e planos futuros.</P>
|
||||
|
||||
<P>Uma solicitação de funcionalidade geralmente resulta em uma das
|
||||
seguintes respostas:</P>
|
||||
<ul>
|
||||
<li>A funcionalidade já está na lista de <A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A></li>
|
||||
<li>A funcionalidade não é desejável porque:
|
||||
<ul>
|
||||
<li>Ela duplica uma funcionalidade existente que já segue o
|
||||
padrão SQL</li>
|
||||
<li>A funcionalidade aumentará a complexidade do código mas
|
||||
adicionará pouco benefício</li>
|
||||
<li>A funcionalidade será insegura ou não-confiável</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li>A nova funcionalidade é adicionada a lista de
|
||||
<A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A></li>
|
||||
</ul>
|
||||
|
||||
<P>O PostgreSQL não utiliza sistema de acompanhamento de bugs porque
|
||||
nós achamos mais eficiente responder diretamente o e-mail e manter a
|
||||
lista de <A href="http://www.postgresql.org/docs/faqs.TODO.html">AFAZERES</A>
|
||||
atualizada. Na prática, bugs não duram muito no programa; e bugs que afetam
|
||||
uma grande quantidade de usuários são corrigidos rapidamente. O único lugar
|
||||
para encontrar todas as mudanças, melhorias e correções em uma versão do
|
||||
PostgreSQL é ler as mensagens de log do
|
||||
<a href="http://www.postgresql.org/developer/sourcecode/">CVS</a>. Até mesmo
|
||||
as notas de lançamento não listam todas as mudanças feitas no programa.</P>
|
||||
|
||||
<H3 id="item1.10">1.10) Que documentação está disponível?</H3>
|
||||
|
||||
<P>O PostgreSQL inclui vasta documentação, incluindo um manual extenso,
|
||||
páginas de manuais (man pages) e alguns exemplos teste. Veja o diretório
|
||||
<I>/doc</I>. Você também pode pesquisar os manuais online em <A href=
|
||||
"http://www.postgresql.org/docs">http://www.postgresql.org/docs</A>.
|
||||
</P>
|
||||
|
||||
<P>Há dois livros sobre PostgreSQL disponíveis online em <A href=
|
||||
"http://www.postgresql.org/docs/books/awbook.html">http://www.postgresql.org/docs/books/awbook.html</A>
|
||||
e <A href=
|
||||
"http://www.commandprompt.com/ppbook/">http://www.commandprompt.com/ppbook/</A>.
|
||||
Há uma lista de livros sobre PostgreSQL disponíveis para compra. Um dos mais
|
||||
populares é o do Korry Douglas. Uma lista de análise sobre os livros pode ser
|
||||
encontrada em <A href=
|
||||
"http://www.postgresql.org/docs/books/">http://www.postgresql.org/docs/books/</A>.
|
||||
Há também uma coleção de artigos técnicos sbore PostgreSQL em <A href="http://www.postgresql.org/docs/techdocs/">http://www.postgresql.org/docs/techdocs/</A>.</P>
|
||||
|
||||
<P>O programa cliente de linha de comando <I>psql</I> tem alguns comandos \d para
|
||||
mostrar informações sobre tipos, operadores, funções, agregações, etc. - utilize \?
|
||||
para mostrar os comandos disponíveis.</P>
|
||||
|
||||
<P>Nosso sítio web contém ainda mais documentação.</P>
|
||||
|
||||
<H3 id="item1.11">1.11) Como eu posso aprender <SMALL>SQL</SMALL>?</H3>
|
||||
|
||||
<P>Primeiro, considere os livros específicos sobre PostgreSQL mencionados
|
||||
acima. Muitos de nossos usuários gostam do <I>The Practical SQL Handbook</I>,
|
||||
Bowman, Judith S., et al., Addison-Wesley. Outros do <I>The
|
||||
Complete Reference SQL</I>, Groff et al., McGraw-Hill.</P>
|
||||
|
||||
<P>Há também bons tutoriais disponíveis online:
|
||||
<UL>
|
||||
<LI> <A href="http://www.intermedia.net/support/sql/sqltut.shtm">http://www.intermedia.net/support/sql/sqltut.shtm</A>
|
||||
</LI>
|
||||
<LI>
|
||||
<A href="http://sqlcourse.com/">http://sqlcourse.com</A>
|
||||
</LI>
|
||||
<LI>
|
||||
<A href="http://www.w3schools.com/sql/default.asp">http://www.w3schools.com/sql/default.asp</A>
|
||||
</LI>
|
||||
<LI><A href=
|
||||
"http://mysite.verizon.net/Graeme_Birchall/id1.html">http://mysite.verizon.net/Graeme_Birchall/id1.html</A>
|
||||
</LI>
|
||||
</UL>
|
||||
|
||||
<H3 id="item1.12">1.12) Como posso submeter uma correção (patch) ou me juntar a equipe de desenvolvimento?</H3>
|
||||
|
||||
<P>Veja a <a href="http://www.postgresql.org/docs/faqs.FAQ_DEV.html">
|
||||
FAQ do Desenvolvedor</A>.</P>
|
||||
|
||||
<H3 id="item1.13">1.13) Como é o PostgreSQL comparado a outros <SMALL>SGBD</SMALL>s?</H3>
|
||||
|
||||
<P>Há várias maneiras de se medir um software: funcionalidades, performance, confiabilidade, suporte e preço.</P>
|
||||
|
||||
<DL>
|
||||
<DT><B>Funcionalidades</B></DT>
|
||||
|
||||
<DD>PostgreSQL tem muitas características presentes em muitos <SMALL>SGBD</SMALL>s comerciais como transações, subconsultas, gatilhos, visões, integridade referencial de chave estrangeira e bloqueio (lock) sofisticado. Nós temos algumas funcionalidades que eles não tem, como tipos definidos pelo usuário, herança, regras e controle de concorrência de múltiplas versões para reduzir bloqueios (locks).<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Performance</B></DT>
|
||||
|
||||
<DD>A performance do PostgreSQL é comparável a outros bancos de dados comerciais e de código livre. Ele é mais rápido em algumas coisas, mais lento em outras. Nossa performance é geralmente +/- 10% comparada a de outros bancos de dados.
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Confiabilidade</B></DT>
|
||||
|
||||
<DD>Nós sabemos que um <SMALL>SGBD</SMALL> deve ser confiável ou ele é inútil. Nós empenhamos em lançar versões bem testadas, de código estável e que tenha o mínimo de bugs. Cada versão tem no mínimo um mês de teste em versão beta, e nosso histórico de versões mostra que nós podemos fornecer versões estáveis e sólidas que estão prontas para uso em produção. Nós acreditamos que somos comparados a nosso favor com outros sistemas de bancos de dados nessa área.<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Suporte</B></DT>
|
||||
|
||||
<DD>Nossas listas de discussão fornecem contato com um grupo de desenvolvedores e usuários para ajudar a resolver muitos problemas encontrados. Enquanto nós não podemos garantir o conserto, <SMALL>SGBD</SMALL>s comerciais nem sempre fornecem também. Com acesso direto aos desenvolvedores, a comunidade de usuários, manuais e o código fonte faz com que o suporte do PostgreSQL seja superior ao de outros <SMALL>SGBD</SMALL>s. Há suporte comercial por incidente disponíveis para aqueles que precisam de um. (Veja <A href="#item1.7">seção 1.7 da FAQ</A>).<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Preço</B></DT>
|
||||
|
||||
<DD>Nós somos livres para uso dele tanto comercial quanto não comercial. Você pode adicionar nosso código ao seu produto sem limitações, exceto aquelas descritas na nossa licença BSD mencionada acima.<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
</DL>
|
||||
|
||||
<H3 id="item1.14">1.14) O PostgreSQL gerenciará mudanças no horário devido ao horário de verão em vários países?</H3>
|
||||
|
||||
<P>Mudanças no horário de verão dos USA foram incluídas nas versões 8.0 .[4+] do PostgreSQL e em todas as versões grandes, i.e. 8.1. Mudanças no Canadá e Austrália Oeste foram incluídas na 8.0.[10+], 8.1.[6+] e em todas as versões grandes subsequentes. Versões do PostgreSQL anteriores a 8.0 utilizam o banco de dados de zona horária do sistema operacional para informações sobre horário de verão.</P>
|
||||
|
||||
<HR>
|
||||
|
||||
<H2 align="center">Perguntas sobre Clientes</H2>
|
||||
|
||||
<H3 id="item2.1">2.1) Quais interfaces estão disponíveis para PostgreSQL?</H3>
|
||||
|
||||
<p>A instalação do PostgreSQL inclui somente as interfaces <SMALL>C</SMALL> e
|
||||
<SMALL>C</SMALL> embutida. Todas as outras interfaces são projetos independentes
|
||||
que podem ser obtidos separadamente; sendo separados permitem que eles tenham
|
||||
suas próprias datas de lançamento e time de desenvolvedores.</P>
|
||||
|
||||
<P>Algumas linguagens de programação como <SMALL>PHP</SMALL> incluem uma
|
||||
interface para PostgreSQL. Interfaces para linguagens como Perl,
|
||||
<SMALL>TCL</SMALL>, Python e muitas outras estão disponíveis em
|
||||
<a href="http://www.pgfoundry.org">http://www.pgfoundry.org</A>.
|
||||
</P>
|
||||
|
||||
<H3 id="item2.2">2.2) Quais ferramentas estão disponíveis para utilizar o PostgreSQL com páginas Web?</H3>
|
||||
|
||||
<P>Uma boa introdução para páginas web que utilizam bancos de dados pode ser vista em:
|
||||
<A href="http://www.webreview.com">http://www.webreview.com</A></P>
|
||||
|
||||
<P>Para integração na Web, PHP (<A
|
||||
href="http://www.php.net">http://www.php.net</A>)
|
||||
é uma excelente interface.</P>
|
||||
|
||||
<P>Para casos complexos, muitos usam a Interface Perl e DBD::Pg com CGI.pm
|
||||
ou mod_perl.</P>
|
||||
|
||||
<H3 id="item2.3">2.3) O PostgreSQL tem interfaces gráficas para iteragir com o usuário?</H3>
|
||||
|
||||
<P>Há um vasto número de Ferramentas Gráficas (GUI), que estão disponíveis
|
||||
para o PostgreSQL, comerciais e de desenvolvedores de código aberto. Uma
|
||||
lista detalhada pode ser encontrada em <A href="http://www.postgresql.org/docs/techdocs.54">
|
||||
Documentação da Comunidade PostgreSQL</A></P>
|
||||
|
||||
<HR>
|
||||
|
||||
<H2 align="center">Perguntas Administrativas</H2>
|
||||
|
||||
<H3 id="item3.1">3.1) Como eu instalo o PostgreSQL em um local diferente de <I>/usr/local/pgsql</I>?</H3>
|
||||
|
||||
<P>Especifique a opção <I>--prefix</I> quando executar o <I>configure</I>.</P>
|
||||
|
||||
<H3 id="item3.2">3.2) Como eu controlo conexões de outras máquinas?</H3>
|
||||
|
||||
<P>Por padrão, o PostgreSQL só permite conexões da máquina local utilizando soquetes de domínio Unix ou conexões TCP/IP. Outras máquinas não poderão conectar-se a menos que você modifique <I>listen_addresses</I> no <I>postgresql.conf</I>, habilite a autenticação por máquina modificando o arquivo <I>$PGDATA/pg_hba.conf</I> e reinicie o servidor PostgreSQL.</P>
|
||||
|
||||
<H3 id="item3.3">3.3) Como eu ajusto o servidor de banco de dados para obter uma performance melhor?</H3>
|
||||
|
||||
<P>Há três grandes áreas para melhorar a performance em potencial:</P>
|
||||
|
||||
<DL>
|
||||
<DT><B>Mudança de Consultas</B></DT>
|
||||
|
||||
<DD>Isto involve modificar consultas para obter melhor performance:
|
||||
<ul>
|
||||
<li>Criação de índices, incluir expressões e índices parciais</li>
|
||||
<li>Utilização o COPY ao invés de múltiplos comandos <SMALL>INSERT</SMALL>s</li>
|
||||
<li>Agrupamento de múltiplos comandos em uma única transação para diminuir
|
||||
a despesa com efetivações (commit)</li>
|
||||
<li>Utilização do <SMALL>CLUSTER</SMALL> quando recuperar vários registros de
|
||||
um índice</li>
|
||||
<li>Utilização do <SMALL>LIMIT</SMALL> para retornar um subconjunto da saída
|
||||
da consulta</li>
|
||||
<li>Utilização de Consultas preparadas</li>
|
||||
<li>Utilização de <SMALL>ANALYZE</SMALL> para manter as estatísticas do
|
||||
otimizador corretas</li>
|
||||
<li>Utilização regular do <SMALL>VACUUM</SMALL> ou <I>pg_autovacuum</I></li>
|
||||
<li>Remoção de índices durante grande mudança de dados</li>
|
||||
</ul><BR>
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Configuração do Servidor</B></DT>
|
||||
|
||||
<DD>Um grande número de configurações que afetam a performance.
|
||||
Para obter detalhes adicionais, veja <a href=
|
||||
"http://www.postgresql.org/docs/current/static/runtime-config.html">
|
||||
Administration Guide/Server Run-time Environment/Run-time
|
||||
Configuration</a> para listagem completa, e para
|
||||
comentários veja <a href=
|
||||
"http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html">
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html</a>
|
||||
e <a href="http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html">
|
||||
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html</a>.
|
||||
<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
|
||||
<DT><B>Seleção do Hardware</B></DT>
|
||||
|
||||
<DD>O efeito do hardware na performance é detalhado em
|
||||
<a href="http://www.powerpostgresql.com/PerfList/">
|
||||
http://www.powerpostgresql.com/PerfList/</a> e <a
|
||||
href="http://momjian.us/main/writings/pgsql/hw_performance/index.html">
|
||||
http://momjian.us/main/writings/pgsql/hw_performance/index.html</a>.
|
||||
<BR>
|
||||
<BR>
|
||||
</DD>
|
||||
</DL>
|
||||
|
||||
<H3 id="item3.4">3.4) Quais características de depuração estão disponíveis?</H3>
|
||||
|
||||
<P>Há muitas variáveis de configuração do servidor <CODE>log_*</CODE>
|
||||
que habilitam a exibição de consultas e estatísticas que podem ser
|
||||
muito úteis para depuração e medidas de performance.</P>
|
||||
|
||||
<H3 id="item3.5">3.5) Por que eu recebo <I>"Sorry, too many clients"</I> quando eu tento conectar?</H3>
|
||||
|
||||
<P>Você atingiu o limite padrão de 100 sessões. Você
|
||||
precisa aumentar o limite do servidor PostgreSQL, que diz
|
||||
quantos processos servidor concorrentes ele pode iniciar, alterando
|
||||
o valor <I>max_connections</I> no <I>postgresql.conf</I> e
|
||||
reiniciando o <I>postmaster</I>.</P>
|
||||
|
||||
<H3 id="item3.6">3.6) Qual é o processo de atualização do PostgreSQL?</H3>
|
||||
|
||||
<P>Veja <a
|
||||
href="http://www.postgresql.org/support/versioning">http://www.postgresql.org/support/versioning</a>
|
||||
para discuss<73>o geral sobre atualiza<7A><61>es e <a href=
|
||||
"http://www.postgresql.org/docs/current/static/install-upgrading.html">
|
||||
http://www.postgresql.org/docs/current/static/install-upgrading.html</a>
|
||||
para instruções específicas.</P>
|
||||
|
||||
<H3 id="item3.7">3.7) Que tipo de hardware eu devo usar?</H3>
|
||||
|
||||
<P>Por causa do hardware de PC ser em sua maioria compatível, pessoas tendem a acreditar que todos os hardwares de PC são de mesma qualidade. Não é verdade. ECC RAM, SCSI e placas mãe de qualidade são mais confiáveis e têm uma melhor performance do que hardwares mais baratos. O PostgreSQL executará em quase todo hardware, mas se a confiabilidade e a performance forem importantes é prudente pesquisar sobre as opções de hardware. Nossas listas de discussão podem ser usadas para discutir opções de hardware e dilemas.</P>
|
||||
|
||||
<HR>
|
||||
|
||||
<H2 align="center">Perguntas Operacionais</H2>
|
||||
|
||||
<H3 id="item4.1">4.1) Como eu faço um <SMALL>SELECT</SMALL> somente dos primeiros registros de uma consulta? Um registro randômico?</H3>
|
||||
|
||||
<P>Para obter somente alguns registros, se você sabe o número de
|
||||
registros necessários ao executar o <SMALL>SELECT</SMALL> utilize
|
||||
o <SMALL>LIMIT</SMALL>. Se um índice corresponde no <SMALL>ORDER
|
||||
BY</SMALL> é possível que a consulta toda não tenha que ser
|
||||
executada. Se você não sabe o número de registros ao executar o
|
||||
<SMALL>SELECT</SMALL>, utilize um cursor e o <SMALL>FETCH</SMALL>.</P>
|
||||
|
||||
<P>Para <SMALL>obter</SMALL> um registro randômico, utilize:</P>
|
||||
<PRE>
|
||||
SELECT col
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1;
|
||||
</PRE>
|
||||
|
||||
<H3 id="item4.2">4.2) Como eu descubro quais tabelas, índices, bancos de dados e usuários estão definidos? Como eu vejo as consultas utilizadas pelo <I>psql</I> para mostrá-los?</H3>
|
||||
|
||||
<P>Utilize o comando \dt para ver tabelas no <I>psql</I>. Para obter
|
||||
uma lista completa dos comandos no psql você pode utilizar \?.
|
||||
Alternativamente, você pode ler o código-fonte do <I>psql</I> no arquivo
|
||||
<I>pgsql/src/bin/psql/describe.c</I>, ele contém os comandos <SMALL>SQL</SMALL>
|
||||
que geram a saída para os comandos de contrabarra do <I>psql</I>. Você
|
||||
também pode iniciar o <I>psql</I> com a opção <I>-E</I> para que as consultas
|
||||
utilizadas para executar os comandos que você informou seja exibida.
|
||||
O PostgreSQL também fornece uma inteface compatível com <SMALL>SQL</SMALL> do
|
||||
INFORMATION SCHEMA que você pode consultar para obter informação sobre o
|
||||
banco de dados.</P>
|
||||
|
||||
<P>Há também tabelas do sistema que começam com <I>pg_</I> que os descrevem
|
||||
também.</P>
|
||||
|
||||
<P>Utilizando o <I>psql -l</I> listará todos os bancos de dados.</P>
|
||||
|
||||
<P>Veja também o arquivo <I>pgsql/src/tutorial/syscat.source</I>. Ele
|
||||
ilustra muitos dos comandos <SMALL>SELECT</SMALL>s necessários para obter
|
||||
informação das tabelas de sistema do banco de dados.</P>
|
||||
|
||||
<H3 id="item4.3">4.3) Como você muda o tipo de dado de uma coluna?</H3>
|
||||
|
||||
<P>Mudar o tipo de dado de uma coluna pode ser feito facilmente na versão 8.0
|
||||
ou superior com <SMALL>ALTER TABLE ALTER COLUMN TYPE</SMALL>.</P>
|
||||
|
||||
<P>Em versões anteriores, faça isso:</P>
|
||||
<PRE>
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN col_nova <i>novo_tipo_dado</i>;
|
||||
UPDATE tab SET col_nova = CAST(col_antiga AS <i>novo_tipo_dado</i>);
|
||||
ALTER TABLE tab DROP COLUMN col_antiga;
|
||||
COMMIT;
|
||||
</PRE>
|
||||
<P>Você pode então querer fazer um <I>VACUUM FULL tab</I> para recuperar
|
||||
o espaço em disco utilizado pelos registros expirados.</P>
|
||||
|
||||
<H3 id="item4.4">4.4) Qual é o tamanho máximo de um registro, uma tabela e um banco de dados?</H3>
|
||||
|
||||
<P>Estes são os limites:</P>
|
||||
<BLOCKQUOTE>
|
||||
<TABLE>
|
||||
<TR><TD>Tamanho máximo de um banco de dados?</TD><TD>ilimitado (existem bancos de dados de 32 TB)</TD></TR>
|
||||
<TR><TD>Tamanho máximo de uma tabela?</TD><TD>32 TB</TD></TR>
|
||||
<TR><TD>Tamanho máximo de um registro?</TD><TD>400 GB</TD></TR>
|
||||
<TR><TD>Tamanho máximo de um campo?</TD><TD>1 GB</TD></TR>
|
||||
<TR><TD>Número máximo de registros em uma tabela?</TD><TD>ilimitado</TD></TR>
|
||||
<TR><TD>Número máximo de colunas em uma tabela?</TD><TD>250-1600 dependendo dos tipos das colunas</TD></TR>
|
||||
<TR><TD>Número máximo de índices em uma tabela?</TD><TD>ilimitado</TD></TR>
|
||||
</TABLE>
|
||||
</BLOCKQUOTE>
|
||||
|
||||
<P>É claro, que eles não são ilimitados, mas limitados
|
||||
ao espaço em disco disponível e espaço em memória/swap.
|
||||
A Performance será penalizada quando estes valores se tornarem grandes.</P>
|
||||
|
||||
<P>O tamanho máximo de uma tabela com 32 TB não requer suporte a
|
||||
arquivos grandes do sistema operacional. Tabelas grandes são armazenadas
|
||||
como múltiplos arquivos de 1 GB então o limite do sistema de
|
||||
arquivos não é importante.</P>
|
||||
|
||||
<P>O tamanho máximo de uma tabela, o tamanho de um registro e o número
|
||||
máximo de colunas podem ser quadruplicados aumentando-se o tamanho padrão
|
||||
do bloco para 32k. O tamanho máximo de uma tabela pode também ser aumentado utilizando
|
||||
particionamento de tabela.</P>
|
||||
|
||||
<P>Uma limitação é que índices não podem ser criados em colunas maiores do que
|
||||
2.000 caracteres. Felizmente, tais índices são raramente necessários. Unicidade é
|
||||
melhor garantida por um índice de uma função de um hash MD5 de uma coluna longa, e
|
||||
indexação de texto longo permite a busca de palavras dentro da coluna.</P>
|
||||
|
||||
<H3 id="item4.5">4.5) Quanto espaço em disco é necessário para armazenar dados de um arquivo texto?</H3>
|
||||
|
||||
<P>Um banco de dados PostgreSQL irá requerer até cinco vezes a quantidade de espaço requerida para armazenar dados em um arquivo texto.</P>
|
||||
|
||||
<P>Como um exemplo, considere um arquivo com 100.000 linhas contendo um inteiro e uma descrição em cada linha. Suponha que o tamanho médio da descrição é de vinte bytes. O arquivo terá 2,8 MB. O tamanho do arquivo do banco de dados PostgreSQL que contém esses dados pode ser estimado em 5,2 MB:</P>
|
||||
<PRE>
|
||||
24 bytes: cada cabeçalho de registro (aproximadamente)
|
||||
24 bytes: um campo int e um campo texto
|
||||
+ 4 bytes: ponteiro na página para a tupla
|
||||
-------------------------------------------
|
||||
52 bytes por registro
|
||||
|
||||
O tamanho de uma página de dados no PostgreSQL é 8192 bytes (8 KB), então:
|
||||
|
||||
8192 bytes por página
|
||||
------------------------ = 158 registros por página do banco de dados (arredondado para baixo)
|
||||
52 bytes por registro
|
||||
|
||||
100000 registros de dados
|
||||
---------------------------- = 633 páginas do banco de dados (arredondado para cima)
|
||||
158 registros por página
|
||||
|
||||
633 páginas do banco de dados * 8192 bytes por página = 5.185.536 bytes (5,2 MB)
|
||||
</PRE>
|
||||
|
||||
<P>Índices não requerem muito espaço, mas contém
|
||||
dados que foram indexados, então eles podem ocupar algum espaço.</P>
|
||||
|
||||
<P><SMALL>NULL</SMALL>s são armazenados como bitmaps, então eles
|
||||
utilizam muito pouco espaço.</P>
|
||||
|
||||
<H3 id="item4.6">4.6) Por que minhas consultas estão lentas? Por que elas não estão utilizando meus índices?</H3>
|
||||
|
||||
<P>Índices não são utilizados por toda consulta. Índices são utilizados somente
|
||||
se a tabela é maior do que um tamanho mínimo, e a consulta seleciona somente uma
|
||||
pequena porcentagem dos registros da tabela. Isto porque o acesso randômico ao
|
||||
disco causado pela busca indexada pode ser mais lento do que uma leitura ao longo
|
||||
da tabela ou busca sequencial.</P>
|
||||
|
||||
<P>Para determinar se um índice deveria ser utilizado, o PostgreSQL deve ter
|
||||
estatísticas sobre a tabela. Estas estatísticas são coletadas utilizando o
|
||||
<SMALL>VACUUM ANALYZE</SMALL> ou simplesmente o <SMALL>ANALYZE</SMALL>.
|
||||
Utilizando estatísticas, o otimizador sbae quantos registros estão na tabela,
|
||||
e pode melhor determinar se índices deveriam ser utilizados.
|
||||
Estatísticas também são úteis para determinar a ordem de junção ótima e métodos
|
||||
de junção. Coleção de estatísticas deveriam ser feitas periodicamente a
|
||||
medida que o conteúdo da tabela muda.</P>
|
||||
|
||||
<P>Índices não são normalmente utilizados para <SMALL>ORDER BY</SMALL> ou para
|
||||
fazer junções. Uma busca sequencial seguido por uma ordenação explícita é
|
||||
geralmente mais rápida do que uma busca indexada em uma tabela grande.
|
||||
Contudo, <SMALL>LIMIT</SMALL> combinado com <SMALL>ORDER BY</SMALL>
|
||||
frequentemente utilizará índice porque somente uma pequena porção da tabela
|
||||
será retornada.</P>
|
||||
|
||||
<P>Se você acredita que o otimizador está incorreto ao escolher uma busca
|
||||
sequencial, utilize <CODE>SET enable_seqscan TO 'off'</CODE> e execute a
|
||||
consulta novamente para ver se uma busca indexada é realmente mais rápida.</P>
|
||||
|
||||
<P>Ao utilizar operadores curinga tais como <SMALL>LIKE</SMALL> ou <I>~</I>,
|
||||
índices podem ser utilizados somente em algumas condições:</P>
|
||||
<UL>
|
||||
<LI>O início da cadeia de caracteres da busca deve ser iniciar com uma
|
||||
cadeia de caracteres, i.e.
|
||||
<UL>
|
||||
<LI>modelos <SMALL>LIKE</SMALL> não devem iniciar com <I>%</I>.</LI>
|
||||
<LI>modelos <I>~</I> (expressões regulares) devem iniciar com <I>^</I>.</LI>
|
||||
</UL></LI>
|
||||
<LI>A cadeia de caracteres utilizada na busca não pode iniciar com a classe de
|
||||
caracteres e.g. [a-e].</LI>
|
||||
<LI>Busca que não diferenciam maiúsculas de minúsculas tais como <SMALL>ILIKE</SMALL> e
|
||||
<I>~*</I> não utilizam índices. Em vez disso, utilize índice de expressão, que
|
||||
é descrito na seção <a href="#item4.8">4.8</a>.</LI>
|
||||
<LI>O idioma padrão <I>C</I> deve ser usando durante o <i>initdb</i>
|
||||
porque não é possível saber o próximo caracter em idiomas que não sejam o C.
|
||||
Você pode criar um índice especial <CODE>text_pattern_ops</CODE> para tais casos
|
||||
que funcionam somente para indexação com <SMALL>LIKE</SMALL>. Também é
|
||||
possível utilizar indexação de busca textual para buscas por palavras.
|
||||
</LI>
|
||||
</UL>
|
||||
|
||||
<P>Em versões anteriores a 8.0, índices frequentemente não podem ser utilizados
|
||||
a menos que os tipos de dados correspondam aos tipos de coluna do índice. Isto era
|
||||
particularmente verdadeiro para índices de coluna int2, int8 e numeric.</P>
|
||||
|
||||
<H3 id="item4.7">4.7) Como eu vejo como o otimizador de consulta está avaliando a minha consulta?</H3>
|
||||
|
||||
<P>Veja o comando <SMALL>EXPLAIN</SMALL> no manual.</P>
|
||||
|
||||
<H3 id="item4.8">4.8) Como eu faço buscas com expressões regulares
|
||||
e buscas com expressões regulares sem diferenciar maiúsculas de minúsculas? Como eu
|
||||
utilizo um índice para buscas que não diferenciam maiúsculas de minúsculas?</H3>
|
||||
|
||||
<P>O operador <I>~</I> faz avaliação de expressões regulares,
|
||||
e <I>~*</I> faz avaliação não sensível a maiúsculas
|
||||
de expressões regulares. A variante não sensível a maiúsculas
|
||||
do <SMALL>LIKE</SMALL> é chamada de <SMALL>ILIKE</SMALL>.</P>
|
||||
|
||||
<P>Comparações de igualdade não sensíveis a maiúsculas
|
||||
são normalmente expressadas como:</P>
|
||||
<PRE>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
</PRE>
|
||||
Isso não irá utilizar o índice padrão. Contudo, se
|
||||
você criar um índice de expressão, ele será utilizado:
|
||||
<PRE>
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
</PRE>
|
||||
<P>Se o índice acima é criado como <SMALL>UNIQUE</SMALL>, embora a
|
||||
coluna possa armazenar caracteres maiúsculos e minúsculos, ele não
|
||||
pode ter valores idênticos que diferem apenas em letras maiúsculas e minúsculas.
|
||||
Para forçar uma letra maiúscula ou minúscula a ser armazenada na coluna, utilize
|
||||
uma restrição <SMALL>CHECK</SMALL> ou um gatilho.</P>
|
||||
|
||||
<H3 id="item4.9">4.9) Em uma consulta, como eu detecto se um campo é <SMALL>NULL</SMALL>? Como eu posso concatenar possíveis <SMALL>NULL</SMALL>s? Como eu posso ordenar por um campo que é <SMALL>NULL</SMALL> ou não?</H3>
|
||||
|
||||
<P>Você testa a coluna com <SMALL>IS NULL</SMALL> e <SMALL>IS
|
||||
NOT NULL</SMALL>, como a seguir:</P>
|
||||
|
||||
<PRE>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
</PRE>
|
||||
|
||||
<P>Para concatenar com possíveis <SMALL>NULL</SMALL>s, utilize <I>COALESCE()</I>, assim:</P>
|
||||
<PRE>
|
||||
SELECT COALESCE(col1, '') || COALESCE(col2, '')
|
||||
FROM tab
|
||||
</PRE>
|
||||
|
||||
<P>Para ordenar pelo status <SMALL>NULL</SMALL>, utilize os modificadores
|
||||
<SMALL>IS NULL</SMALL> e <SMALL>IS NOT NULL</SMALL> na sua cláusula
|
||||
<SMALL>ORDER BY</SMALL>. Coisas que são <I>verdadeiro</I> serão ordenadas acima
|
||||
das coisas que são <I>falso</I>, então a consulta a seguir irá colocar
|
||||
entradas NULL no início da lista de resultados:</P>
|
||||
|
||||
<PRE>
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
</PRE>
|
||||
|
||||
<H3 id="item4.10">4.10) Qual é a diferença entre os vários tipos de dado de caracteres?</H3>
|
||||
<BLOCKQUOTE>
|
||||
<TABLE>
|
||||
<TR><TH>Tipo</TH><TH>Nome Interno</TH><TH>Observação</TH></TR>
|
||||
<TR><TD>VARCHAR(n)</TD><TD>varchar</TD><TD>tamanho especifica o tamanho
|
||||
máximo, sem preenchimento</TD></TR>
|
||||
<TR><TD>CHAR(n)</TD><TD>bpchar</TD><TD>preenchimento em branco para
|
||||
comprimento fixo específico</TD></TR>
|
||||
<TR><TD>TEXT</TD><TD>text</TD><TD>nenhum limite superior específico no
|
||||
comprimento</TD></TR>
|
||||
<TR><TD>BYTEA</TD><TD>bytea</TD><TD>vetor de bytes de comprimento variável
|
||||
(seguro a byte nulo)</TD></TR>
|
||||
<TR><TD>"char"</TD><TD>char</TD><TD>um caracter</TD></TR>
|
||||
</TABLE>
|
||||
</BLOCKQUOTE>
|
||||
|
||||
<P>Você verá o nome interno quando examinar o catálogo do sistema e em algumas mensagens de erro.</P>
|
||||
|
||||
<P>Os primeiros quatro tipos acima são do tipo "varlena" (i.e., os primeiros quatro bytes no disco são o comprimento seguido pelos dados). Consequentemente o espaço atual utilizado é ligeiramente maior do que o tamanho declarado. Contudo, valores longos são também sujeitos a compressão, então o espaço em disco pode também ser bem menor do que o esperado.</P>
|
||||
|
||||
<SMALL>VARCHAR(n)</SMALL> é melhor quando está armazenando cadeias de caracteres de comprimento variável e há um limite de tamanho desta cadeia. <SMALL>TEXT</SMALL> é para cadeias de caracteres de comprimento ilimitado, com o máximo de um gigabyte.
|
||||
<P><SMALL>CHAR(n)</SMALL> é para armazenar cadeias de caracteres que são todas do mesmo tamanho. <SMALL>CHAR(n)</SMALL> preenche com espaços em branco até o tamanho especificado, enquanto o <SMALL>VARCHAR(n)</SMALL> armazena somente os caracteres fornecidos. <SMALL>BYTEA</SMALL> é para armazenar dados binários, particularmente valores que incluem bytes <SMALL>NULL</SMALL>. Todos os tipos descritos aqui tem características de performance similares.</P>
|
||||
|
||||
<H3 id="item4.11.1">4.11.1) Como eu crio um campo serial/auto incremento?</H3>
|
||||
|
||||
<P>PostgreSQL suporta o tipo de dados <SMALL>SERIAL</SMALL>. Ele cria
|
||||
automaticamente uma sequência. Por exemplo:</P>
|
||||
<PRE>
|
||||
CREATE TABLE pessoa (
|
||||
id SERIAL,
|
||||
nome TEXT
|
||||
);
|
||||
</PRE>
|
||||
|
||||
é automaticamente traduzido em:
|
||||
<PRE>
|
||||
CREATE SEQUENCE pessoa_id_seq;
|
||||
CREATE TABLE pessoa (
|
||||
id INT4 NOT NULL DEFAULT nextval('pessoa_id_seq'),
|
||||
nome TEXT
|
||||
);
|
||||
</PRE>
|
||||
|
||||
<P>Sequências automaticamente criadas são nomeadas como
|
||||
<<i>tabela</i>>_<<i>colunaserial</i>>_<i>seq</i>, onde
|
||||
<i>tabela</i> e <i>colunaserial</i> são os nomes da tabela e
|
||||
da coluna serial, respectivamente. Veja a página sobre
|
||||
<I>create_sequence</I> no manual para obter informações
|
||||
adicionais sobre sequências.
|
||||
|
||||
<H3 id="item4.11.2">4.11.2) Como eu consigo o valor de um campo
|
||||
<SMALL>SERIAL</SMALL>?</H3>
|
||||
|
||||
<P>A maneira mais simples de obter o próximo valor <SMALL>SERIAL</SMALL>
|
||||
de uma sequência é com <SMALL>RETURNING</SMALL>. Utilizando o
|
||||
exemplo da tabela em <A href="#item4.11.1">4.11.1</A>, ele ficaria assim:
|
||||
|
||||
<PRE>
|
||||
INSERT INTO pessoa (nome) VALUES ('Blaise Pascal') RETURNING id;
|
||||
</PRE>
|
||||
|
||||
Você também pode chamar <I>nextval()</I> e utilizar o valor no
|
||||
<SMALL>INSERT</SMALL> ou chamar <I>currval()</I> <I>após</I> o
|
||||
<SMALL>INSERT</SMALL>.
|
||||
|
||||
<H3 id="item4.11.3">4.11.3) <I>currval()</I> não lida com condição de corrida com outros usuários?</H3>
|
||||
|
||||
<P>Não. <I>currval()</I> retorna o valor atual atribuido pela sua sessão, e não por todas as sessões.</P>
|
||||
|
||||
<H3 id="item4.11.4">4.11.4) Por que os números da minha sequência não são reutilizados quando uma transação é abortada? Por que há intervalos nos números da minha sequência/coluna SERIAL?</H3>
|
||||
|
||||
<P>Para melhorar a concorrência, valores da sequência são atribuídos a transações correntes e não são travados até que a transação seja finalizada. Isso causa intervalos na numeração por causa de transações abortadas.</P>
|
||||
|
||||
<H3 id="item4.12">4.12) O que é um <SMALL>OID</SMALL>? O que é um <SMALL>CTID</SMALL>?</H3>
|
||||
|
||||
<P>Se uma tabela é criada com <SMALL>WITH OIDS</SMALL>, cada registro recebe um <SMALL>OID</SMALL> único.
|
||||
O<SMALL>ID</SMALL>s são automaticamente atribuídos como inteiros de 4 bytes
|
||||
que são únicos ao longo de toda instalação. Contudo, eles são limitados em
|
||||
4 bilhões e, então, os O<SMALL>ID</SMALL>s começam a ser duplicados. O PostgreSQL
|
||||
utiliza <SMALL>OID</SMALL>s para ligar as tabelas do sistema.</P>
|
||||
|
||||
<P>Para numerar registros nas tabelas do usuários, é melhor utilizar
|
||||
<SMALL>SERIAL</SMALL> ao invés de O<SMALL>ID</SMALL>s porque
|
||||
sequências <SMALL>SERIAL</SMALL> são únicas somente em uma tabela; e
|
||||
são menos propícias a atingir o limite.
|
||||
<SMALL>SERIAL8</SMALL> está disponível para armazenar valores de sequências
|
||||
com oito bytes.</P>
|
||||
|
||||
<P>C<SMALL>TID</SMALL>s são utilizados para identificar registros físicos
|
||||
específicos com valores de block e deslocamento. C<SMALL>TID</SMALL>s mudam
|
||||
após registros serem modificados ou recarregados. Eles são utilizados por
|
||||
índices para apontar registros físicos.</P>
|
||||
|
||||
<H3 id="item4.13">4.13) Por que eu recebo o erro <I>"ERROR: Memory exhausted in AllocSetAlloc()"</I>?</H3>
|
||||
|
||||
<P>Você provavelmente está sem memória virtual no seu sistema, ou o seu núcleo (kernel) tem um limite baixo para certos recursos. Tente isto antes de iniciar o servidor PostgreSQL:</P>
|
||||
<PRE>
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
</PRE>
|
||||
|
||||
Dependendo da sua shell, somente um desses comando terá sucesso, mas ele definirá o segmento de dados do seu processo com um limite maior e talvez permita que a consulta seja feita. Este comando é aplicado ao processo atual e todos os subprocessos criados depois do comando ser executado. Se você tiver problemas com o cliente <SMALL>SQL</SMALL> porque o processo servidor retornou muitos dados, tente-o antes de iniciar o cliente.
|
||||
|
||||
<H3 id="item4.14">4.14) Como eu informo qual versão do PostgreSQL eu estou utilizando?</H3>
|
||||
|
||||
<P>No <I>psql</I>, digite <CODE>SELECT version();</CODE></P>
|
||||
|
||||
<H3 id="item4.15">4.15) Como eu crio uma coluna que conterá por padrão a hora atual?</H3>
|
||||
|
||||
<P>Utilize <I>CURRENT_TIMESTAMP</I>:</P>
|
||||
<PRE>
|
||||
CREATE TABLE teste (x int, modtime timestamp DEFAULT CURRENT_TIMESTAMP );
|
||||
</PRE>
|
||||
|
||||
<H3 id="item4.16">4.16) Como eu faço uma junção externa (outer join)?</H3>
|
||||
|
||||
<P>PostgreSQL suporta junções externas utilizando a sintaxe padrão do SQL. Aqui temos dois exemplos:</P>
|
||||
<PRE>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
</PRE>
|
||||
or
|
||||
<PRE>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
</PRE>
|
||||
|
||||
<P>Essas duas consultas indênticas juntam t1.col com t2.col, e também
|
||||
retornam qualquer registro que não foi juntado em t1 (aqueles que não
|
||||
combinaram com t2). Uma junção a direita <SMALL>RIGHT</SMALL>
|
||||
adicionaria registros que não foram juntados da tabela t2.
|
||||
Uma junção completa (<SMALL>FULL</SMALL>) retornaria os registros
|
||||
combinados mais todos os registros não combinados de t1 e t2.
|
||||
A palavra <SMALL>OUTER</SMALL> é opcional e é assumida nas
|
||||
junções <SMALL>LEFT</SMALL>, <SMALL>RIGHT</SMALL> e <SMALL>FULL</SMALL>.
|
||||
Junções ordinárias são chamadas junções
|
||||
internas (<SMALL>INNER</SMALL>).</P>
|
||||
|
||||
<H3 id="item4.17">4.17) Como eu faço consultas utilizando múltiplos bancos de dados?</H3>
|
||||
|
||||
<P>Não há outra maneira de consultar um banco de dados caso ele
|
||||
não seja o atual. Porque o PostgreSQL carrega catálogos do sistema
|
||||
específicos do banco de dados, é incerto como uma consulta em banco
|
||||
de dados distintos pode se comportar.</P>
|
||||
|
||||
<P><I>contrib/dblink</I> permite consultas em bancos de dados distintos utilizando
|
||||
chamadas de funções. É claro, que um cliente pode fazer
|
||||
conexões simultâneas em bancos de dados diferentes e juntar os
|
||||
resultados no cliente.</P>
|
||||
|
||||
<H3 id="item4.18">4.18) Como eu retorno múltiplos registros ou colunas de uma função?</H3>
|
||||
|
||||
<P>É fácil utilizando funções que retornam conjunto,
|
||||
<a href="http://www.postgresql.org/docs/techdocs.17">
|
||||
http://www.postgresql.org/docs/techdocs.17</a>.</P>
|
||||
|
||||
<H3 id="item4.19">4.19) Por que eu obtenho erros "relation with OID ######
|
||||
does not exist" ao acessar tabelas temporárias em funções PL/PgSQL?</H3>
|
||||
|
||||
<P>Em versões do PostgreSQL < 8.3, PL/PgSQL armazena o conteúdo da função, e o efeito indesejado é que se uma função PL/PgSQL acessa uma tabela temporária, e aquela tabela é removida e criada novamente, e a função é chamada novamente, a função irá falhar porque o conteúdo armazenado da função ainda apontará para a tabela temporária antiga. A solução é utilizar o <SMALL>EXECUTE</SMALL> para acesso a tabelas temporárias no PL/PgSQL. Isto irá fazer com que a consulta seja avaliada toda vez.</P>
|
||||
|
||||
<P>Este problema não ocorre no PostgreSQL 8.3 ou superior.</P>
|
||||
|
||||
<H3 id="item4.20">4.20) Quais soluções de replicação estão disponíveis?</H3>
|
||||
|
||||
<P>Embora "replicação" seja um termo simples, há várias tecnologias para fazer
|
||||
replicação, com vantagens e desvantagens para cada um.</P>
|
||||
|
||||
<P>Replicação mestre/escravo permite que um mestre receba consultas de leitura e
|
||||
escrita, enquanto os escravos só podem aceitar leitura/consultas <SMALL>SELECT</SMALL>.
|
||||
A solução mais popular de replicação mestre-escravo para PostgreSQL disponível livremente
|
||||
é <A href="http://main.slony.info">Slony-I</A>.</P>
|
||||
|
||||
<P>Replicação com múltiplos mestres permite que consultas leitura/escrita sejam
|
||||
enviadas para múltiplos computadores replicadores. Esta capacidade também tem
|
||||
um sério impacto na performance por causa da necessidade de sincronizar as mudanças
|
||||
entre os servidores. <A href="http://pgfoundry.org/projects/pgcluster/">PGCluster</a>
|
||||
é a solução mais popular disponível livremente para PostgreSQL.</P>
|
||||
|
||||
<P>Há também soluções de replicação comerciais e baseadas em hardware disponíveis
|
||||
que suportam uma variedade de modelos de replicação.</P>
|
||||
|
||||
<H3 id="item4.21">4.21) Por que os nomes de minhas tabelas e colunas não
|
||||
são reconhecidos em minha consulta? Por que as maiúsculas não são preservadas?</H3>
|
||||
|
||||
<P>A causa mais comum de nomes desconhecidos é o uso de aspas ao redor dos nomes da tabela ou coluna
|
||||
durante a criação da tabela. Ao utilizar aspas, nomes de tabela e coluna
|
||||
(chamados de identificadores) são armazenados <a
|
||||
href="http://www.postgresql.org/docs/current/static/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS">
|
||||
como especificado</a>, significando que você deve utilizar aspas quando se
|
||||
referir aos nomes na consulta. Algumas interfaces, como pgAdmin,
|
||||
automaticamente colocam aspas nos identificadores durante a criação da tabela.
|
||||
Então, para identificadores serem reconhecidos, você deve:
|
||||
<UL>
|
||||
<LI>Evitar colocar aspas no identificador ao criar tabelas</LI>
|
||||
<LI>Utilizar somente caracteres minúsculos em identificadores</LI>
|
||||
<LI>Colocar aspas em identificadores ao referenciá-los nas consultas</LI>
|
||||
</UL>
|
||||
|
||||
</BODY>
|
||||
</HTML>
|
||||
|
||||
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Load Diff
@ -1,645 +0,0 @@
|
||||
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
||||
<html>
|
||||
<head>
|
||||
<title>PostgreSQL FAQ</title>
|
||||
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||||
<meta http-equiv="Content-language" content="cs">
|
||||
<meta name="description" lang="en" content="Czech translation of FAQ for PostgreSQL">
|
||||
<meta name="description" lang="cs" content="Český překlad FAQ PostgreSQL">
|
||||
</head>
|
||||
<body bgcolor="#ffffff" text="#000000" link="#ff0000" vlink="#a00000" alink="#0000ff">
|
||||
<h1>Frequently Asked Questions</h1>
|
||||
<p><i>Často kladené dotazy (FAQ) PostgreSQL</i>
|
||||
</p>
|
||||
<p>Poslední aktualizace: 29. října 2007 (aktualizováno pro PostgreSQL 8.3)
|
||||
</p>
|
||||
<p>Současný správce: Bruce Momjian (bruce@momjian.us)
|
||||
</p>
|
||||
<p>Přeložil: Pavel Stěhule (pavel.stehule@gmail.com)
|
||||
</p>
|
||||
<p>Nejaktuálnější verzi tohoto dokumentu naleznete na adrese
|
||||
<a href="http://www.postgresql.org/files/documentation/faqs/FAQ.html" title="http://www.postgresql.org/files/documentation/faqs/FAQ.html">http://www.postgresql.org/files/documentation/faqs/FAQ.html</a>
|
||||
</p>
|
||||
<p>Odpovědi na otázky vázané na konkrétní platformy naleznete na
|
||||
adrese <a href="http://www.postgresql.org/docs/faq/" title="http://www.postgresql.org/docs/faq/">http://www.postgresql.org/docs/faq/</a>.
|
||||
</p>
|
||||
<hr>
|
||||
<h2 align="center">Obecné otázky</h2>
|
||||
<a href="#item1.1">1.1</a>) Co je to PostgreSQL? Jaká je správná výslovnost slova PostgreSQL?<br>
|
||||
<a href="#item1.2">1.2</a>) Kdo řídí vývoj PostgreSQL?<br>
|
||||
<a href="#item1.3">1.3</a>) Pod jakou licencí je PostgreSQL?<br>
|
||||
<a href="#item1.4">1.4</a>) Na kterých platformách lze provozovat PostgreSQL?<br>
|
||||
<a href="#item1.5">1.5</a>) Kde mohu získat PostgreSQL?<br>
|
||||
<a href="#item1.6">1.6</a>) Jaká je poslední verze?<br>
|
||||
<a href="#item1.7">1.7</a>) Kde mohu získat podporu?<br>
|
||||
<a href="#item1.8">1.8</a>) Jak a kam hlásit chyby?<br>
|
||||
<a href="#item1.9">1.9</a>) Kde najdu informace o známých chybách nebo nepodporovaných vlastnostech?<br>
|
||||
<a href="#item1.10">1.10</a>) Jaká je dostupná dokumentace?<br>
|
||||
<a href="#item1.11">1.11</a>) Jak se mohu naučit SQL?<br>
|
||||
<a href="#item1.12">1.12</a>) Jak se mohu připojit k týmu vývojářů?<br>
|
||||
<a href="#item1.13">1.13</a>) Jak je na tom PostgreSQL v porovnání s jinými databázemi?<br>
|
||||
<a href="#item1.14">1.14</a>) Je PostgreSQL připraven na aktuální zavádění letního času v některých zemích?<br>
|
||||
<h2 align="center">Dotazy na klientská rozhraní</h2>
|
||||
<a href="#item2.1">2.1</a>) Která rozhraní jsou použitelná pro PostgreSQL?<br>
|
||||
<a href="#item2.2">2.2</a>) Jaké nástroje lze použít pro PostgreSQL a web?<br>
|
||||
<a href="#item2.3">2.3</a>) Existuje grafické rozhraní pro PostgreSQL?<br>
|
||||
<h2 align="center">Administrativní dotazy</h2>
|
||||
<a href="#item3.1">3.1</a>) Jak nainstalovat PostgreSQL jinam než do /usr/local/pgsql?<br>
|
||||
<a href="#item3.2">3.2</a>) Jak nastavit pravidla pro přístup z jiných stanic?<br>
|
||||
<a href="#item3.3">3.3</a>) Jak vyladit databázi na vyšší výkon?<br>
|
||||
<a href="#item3.4">3.4</a>) Jaké mám ladící prostředky?<br>
|
||||
<a href="#item3.5">3.5</a>) Co znamená "Sorry, too many clients", když se zkouším připojit?<br>
|
||||
<a href="#item3.6">3.6</a>) Proč je nutný dump a obnovení (load) databáze při upgradu PostgreSQL?<br>
|
||||
<a href="#item3.7">3.7</a>) Jaký hardware bych měl používat?<br>
|
||||
<h2 align="center">Provozní dotazy</h2>
|
||||
<a href="#item4.1">4.1</a>) Jak získat pouze první řádek dotazu? Náhodný řádek?<br>
|
||||
<a href="#item4.2">4.2</a>) Jak získám seznam tabulek, indexů, databází, a definovaných uživatelů. Mohu vidět dotazy, které používá psql pro zobrazení těchto informací?<br>
|
||||
<a href="#item4.3">4.3</a>) Jak změnit datový typ sloupce?<br>
|
||||
<a href="#item4.4">4.4</a>) Jaká je maximální velikost řádku, tabulky a databáze?<br>
|
||||
<a href="#item4.5">4.5</a>) Kolik diskového prostoru je potřeba k uložení dat z normálního textového souboru?<br>
|
||||
<a href="#item4.6">4.6</a>) Můj dotaz je pomalý a nepoužívá vytvořené indexy. Proč?<br>
|
||||
<a href="#item4.7">4.7</a>) Jak zjistím, jak se vyhodnocuje můj dotaz?<br>
|
||||
<a href="#item4.8">4.8</a>) Jak použít case-(in)sensitive regulární výraz? Jak použít index pro case insensitive hledání?<br>
|
||||
<a href="#item4.9">4.9</a>) Jak v dotazu detekovat, že položka je NULL? Jak bezpečně spojit dva řetězce, pokud mohou obsahovat NULL? Lze třídit podle toho, jestli je položka NULL nebo ne?<br>
|
||||
<a href="#item4.10">4.10</a>) Jaké jsou rozdíly mezi různými znakovými typy?<br>
|
||||
<a href="#item4.11.1">4.11.1</a>) Jak vytvořit serial/auto-increment položku?<br>
|
||||
<a href="#item4.11.2">4.11.2</a>) Jak získat hodnotu SERIAL po vložení řádku?<br>
|
||||
<a href="#item4.11.3">4.11.3</a>) Nezpůsobí currval() a nextval() problémy ve více uživatelském prostředí?<br>
|
||||
<a href="#item4.11.4">4.11.4</a>) Proč není vygenerované číslo použito při přerušení transakce?Proč vznikají díry v číslování prostřednictvím sekvence nebo typu SERIAL?<br>
|
||||
<a href="#item4.12">4.12</a>) Co to je OID? Co je to CTID?<br>
|
||||
<a href="#item4.13">4.13</a>) Co znamená chybové hlášení "ERROR: Memory exhausted in AllocSetAlloc()"?<br>
|
||||
<a href="#item4.14">4.14</a>) Jak zjistím, kterou verzi PostgreSQL používám?<br>
|
||||
<a href="#item4.15">4.15</a>) Jak vytvořit sloupec, který bude implicitně obsahovat aktuální čas?<br>
|
||||
<a href="#item4.16">4.16</a>) Jak provést vnější spojení (outer join)?<br>
|
||||
<a href="#item4.17">4.17</a>) Jak provést dotaz napříč několika databázemi?<br>
|
||||
<a href="#item4.18">4.18</a>) Může funkce vrátit více řádků nebo sloupců?<br>
|
||||
<a href="#item4.19">4.19</a>) Co je příčinou chyby "relation with OID xxxxx does not exist"?<br>
|
||||
<a href="#item4.20">4.20</a>) Jaké jsou možnosti replikace databází?<br>
|
||||
<a href="#item4.21">4.21</a>) Proč v dotazu nejsou rozpoznány názvy mých tabulek nebo funkcí? Proč jsou velká písmena v názvech automaticky převedena na malá písmena?<br>
|
||||
<hr>
|
||||
<h2 align="center">Obecné otázky</h2>
|
||||
<h3><a name="item1.1">1.1</a>) Co je to PostgreSQL? Jaká je správná výslovnost slova PostgreSQL?</h3>
|
||||
<p>Výslovnost PostgreSQL je <i>Post-Gres-Q-L</i>
|
||||
, nebo zjednodušeně <i>Postgres</i>
|
||||
. V řadě jazyků je slovo PostgreSQL obtížně vyslovitelný, proto se v hovoru často používá zjednodušená forma názvu. Pro ty, kteří by si rádi poslechli výslovnost, je k dispozici audiozáznam v <a href="http://www.postgresql.org/files/postgresql.mp3" title="http://www.postgresql.org/files/postgresql.mp3">MP3 formátu</a>.
|
||||
</p>
|
||||
<p>PostgreSQL je relační databáze s některými objektovými rysy, která má možnosti tradičních
|
||||
komerčních databázových systémů s několika rozšířeními, které lze najít v DBMS
|
||||
systémech příští generace. Používání PostgreSQL není omezené a veškeré zdrojové kódy jsou
|
||||
volně dostupné.
|
||||
</p>
|
||||
<p>Za vývojem PostgreSQL je mezinárodní skupina nezávislých vývojářů navzájem komunikujících
|
||||
prostřednictvím internetu. Tento projekt není řízen žádnou obchodní organizací. Pokud se chcete
|
||||
přidat k projektu, přečtěte si vývojářské FAQ na adrese <a href="http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html" title="http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html">http://www.postgresql.org/files/documentation/faqs/FAQ_DEV.html</a> .
|
||||
</p>
|
||||
<h3><a name="item1.2">1.2</a>) Kdo řídí vývoj PostgreSQL?</h3>
|
||||
<p>Pokud budete hledat organizaci řídící vývoj PostgreSQL, budete zklamáni. Nic takového
|
||||
neexistuje. Existují pouze "core" a CVS skupiny uživatelů, ale ty existují více z administrátorských
|
||||
důvodů než z organizačních. Projekt je směrován komunitou vývojářů a uživatelů, ke které se
|
||||
kdokoliv může připojit. Jediné co potřebuje, je přihlásit se do elektronické konference. Více ve
|
||||
<a href="http://www.postgresql.org/docs/faqs.FAQ_DEV.html" title="http://www.postgresql.org/docs/faqs.FAQ_DEV.html">vývojářském FAQ</a>.
|
||||
</p>
|
||||
<h3><a name="item1.3">1.3</a>) Pod jakou licencí je PostgreSQL?</h3>
|
||||
<p>PostgreSQL je předmětem následujících autorských práv:
|
||||
</p>
|
||||
<p>Dílčí Copyright (c) 1996-2009, PostgreSQL Global Development Group<br>
|
||||
Dílčí Copyright (c) 1994-6, Regents of the University of California
|
||||
</p>
|
||||
<p>Uděluje se oprávnění k užití, rozmnožování, provádění úprav a
|
||||
rozšiřování tohoto softwaru a dokumentace k němu, pro jakékoli účely,
|
||||
bez licenčního poplatku a bez písemné licenční smlouvy, za podmínky,
|
||||
že na všech jeho kopiích je uvedeno oznámení o výše uvedených právech,
|
||||
jakož i obsah tohoto a dvou následujících odstavců.
|
||||
</p>
|
||||
<p>THE UNIVERSITY OF CALIFORNIA ("KALIFORNSKÁ UNIVERZITA") NENÍ V ŽÁDNÉM
|
||||
PŘÍPADĚ ODPOVĚDNA ŽÁDNÉ TŘETÍ OSOBĚ ZA PŘÍMOU, NEPŘÍMOU, ZVLÁŠTNÍ,
|
||||
NAHODILOU NEBO VÝSLEDNOU ŠKODU, VČETNĚ UŠLÉHO ZISKU, ZPŮSOBENOU UŽITÍM
|
||||
TOHOTO SOFTWARU A DOKUMENTACE K NĚMU, A TO I V PŘÍPADĚ, ŽE THE
|
||||
UNIVERSITY OF CALIFORNIA BYLA INFORMOVÁNA O MOŽNOSTI VZNIKU TAKOVÉ
|
||||
ŠKODY.
|
||||
</p>
|
||||
<p>THE UNIVERSITY OF CALIFORNIA ZEJMÉNA NEPOSKYTUJE JAKÉKOLI ZÁRUKY, A TO
|
||||
NEJEN ZÁRUKY OBCHODOVATELNOSTI A VHODNOSTI TOHOTO VÝROBKU KE
|
||||
SPECIFICKÝM ÚČELŮM. NÍŽE UVEDENÝ SOFTWARE JE POSKYTNUT "JAK STOJÍ A
|
||||
LEŽÍ" A THE UNIVERSITY OF CALIFORNIA NENÍ POVINNA ZAJISTIT JEHO
|
||||
ÚDRŽBU, PODPORU, AKTUALIZACI, VYLEPŠENÍ NEBO MODIFIKACI.
|
||||
</p>
|
||||
<p>Výše uvedené je BSD licence, běžná licence otevřeného zdroje. Není zde
|
||||
žádné omezení ohledně užití kódu zdroje. Jsme s tím spokojeni a nemáme
|
||||
v úmyslu na této skutečnosti cokoli měnit.
|
||||
</p>
|
||||
<h3><a name="item1.4">1.4</a>) Na kterých platformách lze provozovat PostgreSQL?</h3>
|
||||
<p>Stručně řečeno, PostgreSQL běží na všech moderních unixových systémech. Seznam těch, u kterých proběhlo testování, naleznete v instalačních instrukcích.
|
||||
</p>
|
||||
<p>PostreSQL také běží nativně na všech Microsof Windows systémech odvozených z Microsoft Windows NT jako jsou Windows 2000SP4, WindowsXP a Windows2003. Instalační balíček naleznete na adrese <a href="http://pgfoundry.org/projects/pginstaller" title="http://pgfoundry.org/projects/pginstaller">http://pgfoundry.org/projects/pginstaller</a>. Na starších systémech s ještě MS-DOS jádrem lze spustit PostgreSQL s emulačním programem Cygwin.
|
||||
</p>
|
||||
<p>Dále existuje port pro Novell Netware 6 port na adrese <a href="http://forge.novell.com" title="http://forge.novell.com">http://forge.novell.com</a>, a pro OS/2 verze (eComStation) na adrese <a href="http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgreSQL&stype=all&sort=type&dir=%2F" title="http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgreSQL&stype=all&sort=type&dir=%2F">http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button=Search&key=postgreSQL&stype=all&sort=type&dir=%2F</a> .
|
||||
</p>
|
||||
<h3><a name="item1.5">1.5</a>) Kde mohu získat PostgreSQL?</h3>
|
||||
<p>Pomocí webového klienta z adresy <a href="http://www.postgresql.org/ftp/" title="http://www.postgresql.org/ftp/">http://www.postgresql.org/ftp/</a> nebo klienta ftp z adresy <a href="ftp://ftp.postgresql.org/pub/" title="ftp://ftp.postgresql.org/pub/">ftp://ftp.postgresql.org/pub/</a>.
|
||||
</p>
|
||||
<h3><a name="item1.6">1.6</a>) Jaká je poslední verze?</h3>
|
||||
<p>Nejnovější verzí PostgreSQL je verze 8.2.5
|
||||
</p>
|
||||
<p>V plánu je uvolňovat každoročně jednu velkou verzi a každých několik měsíců malé verze.
|
||||
</p>
|
||||
<h3><a name="item1.7">1.7</a>) Kde mohu získat podporu?</h3>
|
||||
<p>Nejčastější forma podpory uživatelům PostgreSQL komunitou je prostřednictvím e-mailů. Na našem webovém serveru naleznete <a href="http://www.postgresql.org/community/lists/" title="http://www.postgresql.org/community/lists/">odkaz</a> na stránky,kde se můžete přihlásit do elektronické konference. Pro začátek jsou doporučené konference general nebo bugs.
|
||||
</p>
|
||||
<p>Další cestou je IRC kanál #postgresql na Freenode (irc.freenode.net). K připojení použijte Unixový příkaz irc -x '#postgresql' "$USER" irc.freenode.net nebo jakékoholiv jiného IRC klienta. V této síti existuje ještě španělská (#postgresql-es) a francouzská (#postgresqlfr) verze. Další PostgreSQL kanál naleznete na EFNet.
|
||||
</p>
|
||||
<p>Seznam společností poskytující komerční podporu naleznete na adrese <a href="http://techdocs.postgresql.org/companies.php" title="http://techdocs.postgresql.org/companies.php">http://techdocs.postgresql.org/companies.php</a>.
|
||||
</p>
|
||||
<h3><a name="item1.8">1.8</a>) Jak a kam hlásit chyby?</h3>
|
||||
<p>Vyplňte formulář na adrese <a href="http://www.postgresql.org/support/submitbug" title="http://www.postgresql.org/support/submitbug">http://www.postgresql.org/support/submitbug</a>. Na našem ftp serveru <a href="ftp://ftp.postgresql.org/pub/" title="ftp://ftp.postgresql.org/pub/">ftp://ftp.postgresql.org/pub/</a> si ověřte, že používáte aktuální verzi PostreSQL.
|
||||
</p>
|
||||
<p>Chyby reportované prostřednictvím chybového formuláře nebo zasláním mailu do PostgreSQL konference obvykle generuje následující odezvu:
|
||||
</p>
|
||||
<ul><li> Nejedná se o chybu, a proč
|
||||
</li>
|
||||
<li> Jedná se o známou chybu, která je již v seznamu úkolů <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a>
|
||||
</li>
|
||||
<li> Tato chyba byla opravena v aktuální verzi
|
||||
</li>
|
||||
<li> Tato chyba byla již opravena ve verzi, která zatím nebyla oficiálně uvolněna
|
||||
</li>
|
||||
<li> Požadavek na další doplňující informace:
|
||||
<ul><li> Operační systém
|
||||
</li>
|
||||
<li> Verze PostgreSQL
|
||||
</li>
|
||||
<li> Test reprodukující chybu
|
||||
</li>
|
||||
<li> Ladící informace
|
||||
</li>
|
||||
<li> Backtrace výstup debuggeru
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li> Jedná se o zatím nezjištěnou chybu, pak můžete čekat
|
||||
<ul><li> Záplatu odstraňující chybu, která bude vložena do další velké nebo malé verze
|
||||
</li>
|
||||
<li> Informaci, že se jedná o chybu, kterou nelze okamžitě řešit a je proto přidána do <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a>
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
</ul>
|
||||
<h3><a name="item1.9">1.9</a>) Kde najdu informace o známých chybách nebo nepodporovaných vlastnostech?</h3>
|
||||
<p>PostgreSQL podporuje rozšířenou podmnožinu SQL:2003. V našem <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a> naleznete seznam známých chyb, chybějících vlastností, a plány do budoucna.
|
||||
</p>
|
||||
<p>Odezva na požadavek na novou vlastnost PostgreSQL je obvykle:
|
||||
</p>
|
||||
<ul><li> Požadavek je již v <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a>
|
||||
</li>
|
||||
<li> Požadovaná funkce není chtěná protože
|
||||
<ul><li> Duplikuje již existující funkci, která respektuje SQL standard
|
||||
</li>
|
||||
<li> Implementací funkce by se příliš zkomplikoval kód bez relevantního přínosu
|
||||
</li>
|
||||
<li> Funkce by mohla být nebezpečná nebo nespolehlivá
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li> Požadavek je přidán do <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a>
|
||||
</li>
|
||||
</ul>
|
||||
<p>PostgreSQL nepožívá systém pro sledování chyb, protože jsme zjistili, že je efektivnější přímo reagovat na maily a udržovat aktuální <a href="http://www.postgresql.org/docs/faqs.TODO.html" title="http://www.postgresql.org/docs/faqs.TODO.html">TODO</a>. V praxi je snaha o co nejrychlejší řešení chyb, a chyby, které by se mohly projevit u mnoha uživatelů jsou opravovány velice rychle. Jediné místo, kde lze dohledat všechny změny, rozšíření a opravy v PostgreSQL je CVS log. Poznámky k verzi "Release notes" nezachycují všechny změny, k němž došlo.
|
||||
</p>
|
||||
<h3><a name="item1.10">1.10</a>) Jaká je dostupná dokumentace?</h3>
|
||||
<p>PostgreSQL obsahuje vynikající dokumentaci zahrnující manuál, manuálové stránky a testovací příklady. Podívejte se do adresáře /doc. Manuál je přístupný online na <a href="http://www.postgresql.org/docs" title="http://www.postgresql.org/docs">http://www.postgresql.org/docs</a>.
|
||||
</p>
|
||||
<p>K dispozici jsou zdarma dvě online knihy na adresách <a href="http://www.postgresql.org/docs/books/awbook.html" title="http://www.postgresql.org/docs/books/awbook.html">http://www.postgresql.org/docs/books/awbook.html</a> a <a href="http://www.commandprompt.com/ppbook/" title="http://www.commandprompt.com/ppbook/">http://www.commandprompt.com/ppbook/</a>. Další literaturu lze zakoupit. Nejpopulárnější je od Kerryho Douglase. Seznam dostupné literatury je na <a href="http://techdocs.postgresql.org/techdocs/bookreviews.php" title="http://techdocs.postgresql.org/techdocs/bookreviews.php">http://techdocs.postgresql.org/techdocs/bookreviews.php</a>. Ještě je kolekce technicky orientovaných článků tematicky spojených s PostgreSQL na adrese <a href="http://techdocs.postgresql.org/" title="http://techdocs.postgresql.org/">http://techdocs.postgresql.org/</a>.
|
||||
</p>
|
||||
<p>Řádkový klient psql má \d příkazy pro zobrazení informací o typech, operátorech, funkcích, agregačních funkcí, atd. Použijte \? pro zobrazení dostupných příkazů.
|
||||
</p>
|
||||
<p>Další dokumentaci najdete na našem webu.
|
||||
</p>
|
||||
<h3><a name="item1.11">1.11</a>) Jak se mohu naučit SQL?</h3>
|
||||
<p>Podívejte se do výše uvedené dokumentace. Další online knihou je "Teach Yourself SQL in 21 Days, Second Edition" na adrese <a href="http://members.tripod.com/er4ebus/sql/index.htm" title="http://members.tripod.com/er4ebus/sql/index.htm">http://members.tripod.com/er4ebus/sql/index.htm</a>. Mnoho našich uživatelů doporučuje knihu The Practical SQL Handbook, Bowman, Judith S., et al., Addison-Wesley. Další The Complete Reference SQL, Groff et al., McGraw-Hill.
|
||||
</p>
|
||||
<p>Další online tutoriály jsou dostupné na adresách:
|
||||
</p>
|
||||
<ul><li> <a href="http://www.intermedia.net/support/sql/sqltut.shtm" title="http://www.intermedia.net/support/sql/sqltut.shtm">http://www.intermedia.net/support/sql/sqltut.shtm</a>
|
||||
</li>
|
||||
<li> <a href="http://sqlcourse.com" title="http://sqlcourse.com">http://sqlcourse.com</a>
|
||||
</li>
|
||||
<li> <a href="http://www.w3schools.com/sql/default.asp" title="http://www.w3schools.com/sql/default.asp">http://www.w3schools.com/sql/default.asp</a>
|
||||
</li>
|
||||
<li> <a href="http://mysite.verizon.net/Graeme_Birchall/id1.html" title="http://mysite.verizon.net/Graeme_Birchall/id1.html">http://mysite.verizon.net/Graeme_Birchall/id1.html</a>
|
||||
</li>
|
||||
</ul>
|
||||
<h3><a name="item1.12">1.12</a>) Jak se mohu připojit k týmu vývojářů?</h3>
|
||||
<p>Prostudujte si <a href="http://www.postgresql.org/docs/faqs.FAQ_DEV.html" title="http://www.postgresql.org/docs/faqs.FAQ_DEV.html">Developer's FAQ</a>.
|
||||
</p>
|
||||
<h3><a name="item1.13">1.13</a>) Jak je na tom PostgreSQL v porovnání s jinými databázemi?</h3>
|
||||
<p>Software můžeme porovnávat z několika různých pohledů: vlastnosti, výkon, spolehlivost, podpora a cena.
|
||||
</p>
|
||||
<script></script>
|
||||
<h4> Vlastnosti </h4>
|
||||
<p>PostgreSQL nabízí většinu funkcí funkcionality velkých komerčních DBMS systémů jako jsou: transakce, vnořené dotazy, spouště, referenční integrita a sofistikovaný systém zamykání. Poskytujeme určité funkce, které ostatní systémy běžně nepodporují. Např. uživatelem definované typy, dědičnost, pravidla (rules), a MVCC architekturu.
|
||||
</p>
|
||||
<h4> Výkon </h4>
|
||||
<p>Výkon PostgreSQL je srovnatelný s ostatními komerčními nebo Open Source databázemi. V některých případech je rychlejší, jindy pomalejší. Náš výkon je obvykle +/-10% vůči ostatním databázím.
|
||||
</p>
|
||||
<h4> Spolehlivost </h4>
|
||||
<p>Uvědomujeme si, že databáze musí být stoprocentně spolehlivá, jinak je nepoužitelná. Snažíme se, aby každá verze byla dobře otestována a obsahovala minimum chyb. Každá verze je minimálně několik měsíců v beta testovacím režimu. Do produkčního režimu se dostane, až když nedochází k dalším změnám nebo opravám. Věříme, že jsem více než srovnatelní s ostatními databázemi v této oblasti.
|
||||
</p>
|
||||
<h4> Podpora </h4>
|
||||
<p>Na našich internetových konferencích se setkává velká skupina vývojářů a uživatelů při řešení vyskytujících se problémů.
|
||||
Naše internetové konference umožňují kontakt velké skupiny vývojářů a uživatelů. Nemůžeme garantovat opravu chyby, ale komerční DBMSs také vždy negarantují řešení problémů. Věříme ale, že díky přímému kontaktu na vývojáře, naši uživatelskou komunitu, manuálům, a dostupným zdrojovým kódům máme lepší podporu než ostatní DBMSs. Pro ty, kteří preferují komerční "per-incident" podporu, existuje společností, kteří ji nabízejí (FAQ sekce 1.7.)
|
||||
</p>
|
||||
<h4> Cena </h4>
|
||||
<p>PostgreSQL lze používat bezplatně (a to i pro komerční použití). Také můžete neomezeně používat náš kód ve svých produktech s výjimkami specifikovanými v naší licenci (přebíráme BSD licenci).
|
||||
</p>
|
||||
<h3><a name="item1.14">1.14</a>) Je PostgreSQL připraven na aktuální zavádění letního času v některých zemích?</h3>
|
||||
<p>Počínaje verzí 8.0.[4+] podporuje PostgreSQL letní čas také pro USA. Podpora letního času (daylight saving time) pro Kanadu a Západní Austrálii je obsažena ve verzích 8.0.[10+] a 8.1.[6+] a všech následujících verzích. Starší verze používaly systémovou databázi časových zón obsahující, kromě jiného, informaci o tom, zda se pro danou časovou zónu rozlišuje mezi letním a zimním časem.
|
||||
</p>
|
||||
<hr>
|
||||
<h2 align="center">Dotazy na klientská rozhraní</h2>
|
||||
<h3><a name="item2.1">2.1</a>) Která rozhraní jsou použitelná pro PostgreSQL?</h3>
|
||||
<p>PostgreSQL se distribuuje pouze s rozhraním pro jazyk C a embedded C. Všechna další rozhraní představují nezávislé projekty, které je třeba stáhnout z internetu samostatně. Osamostatnění těchto projektů umožňuje nezávislost vývojových týmů a možnost vydávat nové verze bez ohledu na vydání nové verze PostgreSQL.
|
||||
</p>
|
||||
<p>Některé programovací jazyky jako je např. PHP obsahují rozhraní pro PostgreSQL. Rozhraní pro jazyky jako je Perl, Tcl, Python a mnoho dalších jsou dostupné na adrese: <a href="http://gborg.postgresql.org" title="http://gborg.postgresql.org">http://gborg.postgresql.org</a> v sekci Drivers/Interfaces.
|
||||
</p>
|
||||
<h3><a name="item2.2">2.2</a>) Jaké nástroje lze použít pro PostgreSQL a web?</h3>
|
||||
<p>Dobrým úvodem do problematiky databází v prostředí webových stránek může být web <a href="http://www.webreview.com" title="http://www.webreview.com">http://www.webreview.com</a>.
|
||||
</p>
|
||||
<p>PHP (<a href="http://www.php.net" title="http://www.php.net">http://www.php.net</a>) je vynikajícím rozhraním pro tvorbu webů.
|
||||
</p>
|
||||
<p>Pro složitější úlohy se často používá Perl a jeho BDB:Pg rozhraní s podporou CGI - CGI.pm nebo mod_perl(u).
|
||||
</p>
|
||||
<h3><a name="item2.3">2.3</a>) Existuje grafické rozhraní pro PostgreSQL?</h3>
|
||||
<p>K dispozici je řada grafických nástrojů podporujících PostgreSQL a to od komerčních nebo open source vývojářů. Podrobný seznam naleznete na adrese
|
||||
<a href="http://www.postgresql.org/docs/techdocs.54" title="http://www.postgresql.org/docs/techdocs.54">http://www.postgresql.org/docs/techdocs.54</a>.
|
||||
</p>
|
||||
<hr>
|
||||
<h2 align="center">Administrativní dotazy</h2>
|
||||
<h3><a name="item3.1">3.1</a>) Jak nainstalovat PostgreSQL jinam než do /usr/local/pgsql?</h3>
|
||||
<p>Při spouštění configure nastavte parametr --prefix
|
||||
</p>
|
||||
<h3><a name="item3.2">3.2</a>) Jak nastavit pravidla pro přístup z jiných stanic?</h3>
|
||||
<p>Ve výchozí konfiguraci, PostgreSQL umožňuje pouze připojení z lokálního uživatele prostřednictvím Unix domain sockets nebo TCP/IP spojení. Bez modifikace listen_addresses v souboru postgresql.conf, a povolení adresy v souboru $PGDATA/pg_hba.conf se nelze připojit k PostgreSQL z ostatních stanic. Změna výše zmíněných parametrů vyžaduje restart databázového serveru.
|
||||
</p>
|
||||
<h3><a name="item3.3">3.3</a>) Jak vyladit databázi na vyšší výkon?</h3>
|
||||
<p>Výkon systému můžete ovlivnit ve třech oblastech:
|
||||
</p>
|
||||
<h4> Změny dotazu </h4>
|
||||
<ul><li> Použitím indexů včetně částečných a funkcionálních
|
||||
</li>
|
||||
<li> Použitím COPY místo opakovaných INSERTů
|
||||
</li>
|
||||
<li> Sloučením mnoha SQL příkazů do jedné transakce snížením režie na commit
|
||||
</li>
|
||||
<li> Používáním CLUSTERU, pokud načítáte větší počet řádek podle indexu
|
||||
</li>
|
||||
<li> Použitím klauzule LIMIT v poddotazech
|
||||
</li>
|
||||
<li> Použitím předpřipravených dotazů
|
||||
</li>
|
||||
<li> Používáním ANALYZE. Tento příkaz aktualizuje statistiky, které se používají při optimalizaci dotazu
|
||||
</li>
|
||||
<li> Pravidelné použití VACUUM nebo používání pg_autovacuum
|
||||
</li>
|
||||
<li> Odstraněním indexů před rozsáhlými změnami v datech
|
||||
</li>
|
||||
</ul>
|
||||
<h4> Konfigurace serveru </h4>
|
||||
<p>Určité parametry v souboru postgresql.conf mají vliv na výkon serveru. Detaily naleznete v příručce Administrátora v Server Run-time Environment/Run-time Configuration. Další komentáře naleznete v <a href="http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html" title="http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html">http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html</a> a <a href="http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html" title="http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html">http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html</a>.
|
||||
</p>
|
||||
<h4> Výběr hardware </h4>
|
||||
<p>Vliv hardware na výkon serveru je popsán v dokumentech <a href="http://candle.pha.pa.us/main/writings/pgsql/hw_performance/index.html" title="http://candle.pha.pa.us/main/writings/pgsql/hw_performance/index.html">http://candle.pha.pa.us/main/writings/pgsql/hw_performance/index.html</a> a <a href="http://www.powerpostgresql.com/PerfList/" title="http://www.powerpostgresql.com/PerfList/">http://www.powerpostgresql.com/PerfList/</a>.
|
||||
</p>
|
||||
<h3><a name="item3.4">3.4</a>) Jaké mám ladící prostředky?</h3>
|
||||
<p>Nastavením log_* proměnných v konfiguraci serveru si vynutíte logování dotazů a procesních statistik, které Vám mohou pomoci při ladění a optimalizaci výkonu.
|
||||
</p>
|
||||
<h3><a name="item3.5">3.5</a>) Co znamená "Sorry, too many clients", když se zkouším připojit?</h3>
|
||||
<p>Překročil jste výchozí limit, který je 100 současně připojených uživatelů. V konfiguraci serveru v postgresql.conf tuto hodnotu můžete zvětšit změnou hodnoty max_connection. Nezapomeňte restartovat server.
|
||||
</p>
|
||||
<h3><a name="item3.6">3.6</a>) Proč je nutný dump a obnovení (load) databáze při upgradu PostgreSQL?</h3>
|
||||
<p>Způsob číslování je popsán v dokumentaci na <a href="http://www.postgresql.org/support/versioning" title="http://www.postgresql.org/support/versioning">http://www.postgresql.org/support/versioning</a>. Instrukce k provedení migrace na vyšší verzi jsou taktéž v dokumentaci na adrese <a href="http://www.postgresql.org/docs/current/static/install-upgrading.html" title="http://www.postgresql.org/docs/current/static/install-upgrading.html">http://www.postgresql.org/docs/current/static/install-upgrading.html</a>.
|
||||
</p>
|
||||
<h3><a name="item3.7">3.7</a>) Jaký hardware bych měl používat?</h3>
|
||||
<p>Jelikož PC jsou většinou kompatibilní, lidé mají tendence věřit, že všechna PC jsou stejně kvalitní. Což není pravda. Paměti ECC, SCSI a kvalitní základní desky jsou mnohem spolehlivější a výkonnější než lacinější hardware. PostgreSQL poběží na většině hardwaru, nicméně pokud je pro Vás spolehlivost a výkon systému důležitá, je dobré věnovat čas nalezení vhodné hardwarové konfigurace. Na našich elektronických konferencích můžete diskutovat o vhodných konfiguracích a značkách.
|
||||
</p>
|
||||
<hr>
|
||||
<h2 align="center">Provozní dotazy</h2>
|
||||
<h3><a name="item4.1">4.1</a>) Jak získat pouze první řádek dotazu? Náhodný řádek?</h3>
|
||||
<p>Pokud potřebujete pouze několik řádků a pokud víte kolik, použijte
|
||||
SELECT LIMIT. Pokud bude možné použít index shodující se s ORDER BY,
|
||||
je možné, že se nebude provádět celý dotaz. Pokud neznáte počet záznamů,
|
||||
použijte kurzor a příkaz FETCH.
|
||||
</p>
|
||||
<p>Pro výběr náhodného řádku použijte příkaz ve tvaru:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT col
|
||||
FROM tab
|
||||
ORDER BY random()
|
||||
LIMIT 1;
|
||||
</pre>
|
||||
<h3><a name="item4.2">4.2</a>) Jak získám seznam tabulek, indexů, databází, a definovaných uživatelů. Mohu vidět dotazy, které používá psql pro zobrazení těchto informací?</h3>
|
||||
<p>V psql příkazem \dt získáte seznam tabulek. Úplný seznam příkazů psql získáte příkazem \?. Alternativně si můžete prostudovat zdrojový kód psql - soubor pgsql/src/bin/psql/describe.c, který obsahuje SQL příkazy, které jsou generovány pro získání výstupu psql "backslash" příkazů. Také můžete nastartovat psql s parametrem -E, který způsobí zobrazení všech SQL příkazů, které se odesílají na server. PostgreSQL také podporuje SQL standard INFORMAČNÍ SCHÉMATA (standardní systémové tabulky). Klasickým dotazem do systémových tabulek získáte požadované informace o struktuře databáze.
|
||||
</p>
|
||||
<p>Systémové tabulky PostgreSQL (mimo rámec SQL standardů) používají prefix pg_. Pro zjištění struktury databáze je můžete použít také, i když preferovány jsou dotazy do informačního schématu.
|
||||
</p>
|
||||
<p>Seznam všech databází získáte příkazem psql -l
|
||||
</p>
|
||||
<p>Další inspiraci najdete v souboru pgsql/src/tutorial/syscat.source. Obsahuje ilustrační SELECTy potřebné k získání informací z systémových tabulek databáze.
|
||||
</p>
|
||||
<h3><a name="item4.3">4.3</a>) Jak změnit datový typ sloupce?</h3>
|
||||
<p>Ve verzích 8.0 a pozdějších jednoduše:
|
||||
</p>
|
||||
<pre>
|
||||
ALTER TABLE ALTER COLUMN TYPE
|
||||
</pre><p>V starších verzích:
|
||||
</p>
|
||||
<pre>
|
||||
BEGIN;
|
||||
ALTER TABLE tab ADD COLUMN new_col new_data_type;
|
||||
UPDATE tab SET new_col = CAST(old_col AS new_data_type);
|
||||
ALTER TABLE tab DROP COLUMN old_col;
|
||||
COMMIT;
|
||||
</pre><p>Po změně spusťte příkaz VACUUM FULL, aby došlo k uvolnění diskového prostoru použitého v tu chvíli již neplatnými záznamy.
|
||||
</p>
|
||||
<h3><a name="item4.4">4.4</a>) Jaká je maximální velikost řádku, tabulky a databáze?</h3>
|
||||
<p>PostgreSQL má tato omezení:
|
||||
</p>
|
||||
<table border="0">
|
||||
<tr><td> Maximální velikost databáze: </td><td> neomezena (existují 32TB db)
|
||||
</td></tr>
|
||||
<tr><td> Maximální velikost tabulky: </td><td> 32 TB
|
||||
</td></tr>
|
||||
<tr><td> Maximální velikost řádky: </td><td> 480GB
|
||||
</td></tr>
|
||||
<tr><td> Maximální velikost položky </td><td> 1 GB
|
||||
</td></tr>
|
||||
<tr><td> Maximální počet řádků v tabulce: </td><td> neomezeno
|
||||
</td></tr>
|
||||
<tr><td> Maximální počet sloupců v tabulce: </td><td> 250-1600 podle typů
|
||||
</td></tr>
|
||||
<tr><td> Maximální počet indexů na tabulce: </td><td> neomezeno
|
||||
</td></tr>
|
||||
</table>
|
||||
<p>Ve skutečnosti nic není neomezeno, limitem bývá vždy dostupná disková
|
||||
paměť nebo velikost operační paměti. Pokud máte některou z těchto
|
||||
hodnot neobvykle velkou, může dojít ke snížení výkonu.
|
||||
</p>
|
||||
<p>Maximální velikost tabulky je 32 TB a nevyžaduje podporu velkých
|
||||
souborů operačním systémem. Velké tabulky se ukládají do několika 1 GB
|
||||
souborů takže limity souborového systému nejsou podstatné.
|
||||
</p>
|
||||
<p>Maximální velikost tabulky a maximální počet sloupců můžeme
|
||||
zečtyřnásobit nastavením velikosti bloku na 32K.
|
||||
</p>
|
||||
<p>Indexy jsou povolené pouze na sloupcích jejichž délka je menší než 2000 znaků. Pokud tuto délku překročíme a index potřebujeme pro zajištění jednoznačnosti, je vhodnější použít funkcionální index nad MD5 funkcí nebo fulltextový index.
|
||||
</p>
|
||||
<h3><a name="item4.5">4.5</a>) Kolik diskového prostoru je potřeba k uložení dat z normálního textového souboru?</h3>
|
||||
<p>PostgreSQL vyžaduje až pětinásobek diskového prostoru k uložení dat z
|
||||
textového souboru.
|
||||
</p>
|
||||
<p>Například, uvažujme soubor se 100 tisíci řádky obsahující na každé
|
||||
řádce celé číslo a textový popis. Text je v průměrně dvacet bytů
|
||||
dlouhý. Textový soubor bude 2.8 MB dlouhý. Velikost databáze
|
||||
obsahující odpovídající data bude zhruba 5.2 MB.
|
||||
</p>
|
||||
<pre>
|
||||
24 bytů: hlavička řádku (přibližně)
|
||||
24 bytů: jedna celočíselná položka a jedna textová
|
||||
+ 4 byty: ukazatel na stránku k entici
|
||||
------------------------------------------------------
|
||||
52 bytů na řádek
|
||||
</pre><p>Velikost datové stránky PostgreSQL je 8192 bytů (8KB)
|
||||
</p>
|
||||
<pre>
|
||||
8192 bytů na stránce
|
||||
---------------------- = 158 řádek na stránku
|
||||
52 bytů za řádek
|
||||
|
||||
100000 řádek
|
||||
----------------------- = 633 stránek (zaokrouhleno nahoru)
|
||||
158 řádek na stránce
|
||||
|
||||
633 datových stránek * 8192 bytů na každou stránku = 5,185,536 bytů (5.2 MB)
|
||||
</pre><p>Indexy nemají tak velkou režii, ale mohou být také velké, protože
|
||||
obsahují indexovaná data.
|
||||
</p>
|
||||
<p>Hodnoty NULL jsou uloženy v bitmapách, takže zabírají jen velmi málo
|
||||
diskového prostoru.
|
||||
</p>
|
||||
<h3><a name="item4.6">4.6</a>) Můj dotaz je pomalý a nepoužívá vytvořené indexy. Proč?</h3>
|
||||
<p>Každý dotaz nemusí nutně použít existující indexy. Index se použije
|
||||
tehdy, když je tabulka větší než určitá minimální velikost, a dotaz
|
||||
vybírá pouze procentuálně malou část řádků tabulky. To proto, že
|
||||
náhodný přístup k disku daný čtením indexu může být pomalejší než
|
||||
lineární čtení tabulky nebo sekvenční čtení.
|
||||
</p>
|
||||
<p>PostgreSQL rozhoduje o použití indexů na základě statistiky přístupů k
|
||||
tabulce. Tyto statistiky se shromažďují příkazy VACUUM ANALYZE nebo
|
||||
ANALYZE. Díky statistikám má optimizer informaci o počtu řádek v
|
||||
tabulce a může lépe rozhodnout o použití indexů. Statistiky se uplatní
|
||||
při určení optimálního pořadí a metody spojení tabulek. Statistiky by
|
||||
se měli aktualizovat opakovaně, tak jak se mění obsah tabulek.
|
||||
</p>
|
||||
<p>Indexy nejsou obyčejně použity pro setřídění nebo spojení tabulek.
|
||||
Sekvenční zpracování následované explicitním tříděním je obyčejně
|
||||
rychlejší než použití indexu na velké tabulce.
|
||||
</p>
|
||||
<p>Jinak je tomu v případě použití LIMIT a ORDER BY, při kterém se
|
||||
většinou index použije, jelikož je výsledkem pouze malá část tabulky.
|
||||
</p>
|
||||
<p>Pokud si myslíte, že optimizer mylně zvolil sekvenční prohledávání
|
||||
tabulky, použijte příkaz SET enable_seqscan TO 'off' a zkuste zda je
|
||||
prohledávání s indexem rychlejší.
|
||||
</p>
|
||||
<p>Při vyhledávání na základě vzoru jako je např. operátor LIKE nebo ~ se
|
||||
indexy použijí pouze za určitých skutečností:
|
||||
</p>
|
||||
<ul><li> začátek hledaného vzoru musí být ukotven k začátku, tj.
|
||||
<ul><li> vzor LIKE nesmí začínat %
|
||||
</li>
|
||||
<li> ~ regulární výraz musí začínat ^
|
||||
</li>
|
||||
</ul>
|
||||
</li>
|
||||
<li> vzor nesmí začínat intervalem, např. [a-e]
|
||||
</li>
|
||||
<li> vyhledávaní, které není Case sensitiv jako je ILIKE nebo ~* nepoužívá indexy. Můžete ale použít funkcionální indexy, které jsou popsány v sekci 4.8
|
||||
</li>
|
||||
<li> při inicializaci databáze (initdb) musí být použito C locale nebo vytvořte speciální text_pattern_index, který umožní, při respektování zmíněných podmínek použití indexu operací LIKE. Pro vyhledávání celých slov je možné a výhodné použít fulltext.
|
||||
</li>
|
||||
</ul>
|
||||
<h3><a name="item4.7">4.7</a>) Jak zjistím, jak se vyhodnocuje můj dotaz?</h3>
|
||||
<p>Podívejte se do nápovědy k příkazu EXPLAIN.
|
||||
</p>
|
||||
<h3><a name="item4.8">4.8</a>) Jak použít case-(in)sensitive regulární výraz? Jak použít index pro case insensitive hledání?</h3>
|
||||
<p>Vyhledávání prostřednictvím regulárních vzorů zajišťuje operátor ~, který je case-sensitive. Jeho case-insensitive varianta je operátor ~*. Case-insensitive variací operátoru LIKE je operátor ILIKE.
|
||||
</p>
|
||||
<p>Case-insensitive vyhledání se řeší:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE lower(col) = 'abc';
|
||||
</pre><p>Tento dotaz nepoužije standardní index. Musíte použít tzv. funkcionální index:
|
||||
</p>
|
||||
<pre>
|
||||
CREATE INDEX tabindex ON tab (lower(col));
|
||||
</pre><p>Pokud index vytvoříme jako unikátní, tak můžeme ukládat řetězce obsahující malá i velká písmena, ale nikoliv řetězce, které se od sebe odlišují jen v malých a velkých písmenech. K zajištění zápisu řetězce obsahující pouze malá nebo pouze velká písmena použijte CHECK kontroly nebo triggery.
|
||||
</p>
|
||||
<h3><a name="item4.9">4.9</a>) Jak v dotazu detekovat, že položka je NULL? Jak bezpečně spojit dva řetězce, pokud mohou obsahovat NULL? Lze třídit podle toho, jestli je položka NULL nebo ne?</h3>
|
||||
<p>Pokud chcete testovat hodnotu NULL použijte operátor IS:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT *
|
||||
FROM tab
|
||||
WHERE col IS NULL;
|
||||
</pre><p>K spojení řetězců, které mohou obsahovat hodnotu NULL, používejte funkci COALESCE(), např.:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT COALESCE(col1, '') || COALESCE(col2, '')
|
||||
FROM tab
|
||||
</pre><p>Pokud chcete třídit podle hodnoty NULL, použijte výraz IS NULL nebo IS NOT NULL v klauzuli ORDER. Hodnota pravda má přednost před hodnotou false a tedy pokud použijete:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT *
|
||||
FROM tab
|
||||
ORDER BY (col IS NOT NULL)
|
||||
</pre><p>tak záznamy s NULL budou na začátku setříděných dat.
|
||||
</p>
|
||||
<h3><a name="item4.10">4.10</a>) Jaké jsou rozdíly mezi různými znakovými typy?</h3>
|
||||
<table border="0">
|
||||
<tr><td>Typ </td><td> Interní název </td><td> Poznámky
|
||||
</td></tr>
|
||||
<tr><td> VARCHAR(n)</td><td> varchar</td><td> n určuje maximální délku
|
||||
</td></tr>
|
||||
<tr><td> CHAR(n)</td><td> bpchar </td><td> řetězec je do dané délky rozšířen mezerami
|
||||
</td></tr>
|
||||
<tr><td> TEXT</td><td> text</td><td> bez omezení délky
|
||||
</td></tr>
|
||||
<tr><td> BYTEA</td><td> bytea</td><td> pole bytů nespecifikované délky
|
||||
</td></tr>
|
||||
<tr><td> "char"</td><td> char</td><td> jeden znak
|
||||
</td></tr>
|
||||
</table>
|
||||
<p>Na interní názvy můžete narazit v systémovém katalogu nebo v některých chybových hlášeních.
|
||||
</p>
|
||||
<p>Čtyři první typy jsou tzv. varlena typy (první čtyři byty na disku jsou obsahují délku, ostatní obsahují vlastní data). Skutečně obsazený prostor je tedy o něco málo větší než deklarovaná velikost. Na druhou stranu, delší řetězce jsou komprimovány, takže obsazený prostor na disku může být menší než se čeká.
|
||||
</p>
|
||||
<p>VARCHAR(n) je vhodný pro ukládání různě dlouhých řetězců u kterých známe délkové omezení, TEXT pro řetězce bez omezení délky (maximum je jeden gigabyte).
|
||||
</p>
|
||||
<p>CHAR(n) se používá pro uložení stejně dlouhých řetězců. CHAR(n) doplní mezerami na specifikovanou délku, VARCHAR(n) hodnoty se ukládají tak jak jsou. BYTEA je pro ukládání binárních dat - non ASCII hodnot. Všechny zmíněné typy mají podobné výkonové charakteristiky.
|
||||
</p>
|
||||
<h3><a name="item4.11.1">4.11.1</a>) Jak vytvořit serial/auto-increment položku?</h3>
|
||||
<p>V PostgreSQL můžete použít datový typ SERIAL. Jeho použitím se automaticky vytvoří sekvence.
|
||||
Například:
|
||||
</p>
|
||||
<pre>
|
||||
CREATE TABLE person (
|
||||
id SERIAL,
|
||||
name TEXT
|
||||
);
|
||||
</pre><p>je automaticky transformováno na:
|
||||
</p>
|
||||
<pre>
|
||||
CREATE SEQUENCE person_id_seq;
|
||||
CREATE TABLE person (
|
||||
id INT4 NOT NULL DEFAULT nextval('person_id_seq'),
|
||||
name TEXT
|
||||
);
|
||||
</pre><p>Podrobnější informace najdete v manuálu v popisu příkazu create_sequence.
|
||||
</p>
|
||||
<h3><a name="item4.11.2">4.11.2</a>) Jak získat hodnotu SERIAL po vložení řádku?</h3>
|
||||
<p>Nejjednodušším způsob, jak získat vygenerovanou hodnotu typu SERIAL, je využít klauzuli RETURNING. Pro tabulku z 4.11.1 vypadá takto:
|
||||
</p>
|
||||
<pre>
|
||||
INSERT INTO person (name) VALUES ('Blaise Pascal') RETURNING id;
|
||||
</pre><p>Také můžete použít funkci nextvall() a její výsledek použít v příkazu INSERT, nebo zavolat currval() po provedení příkazu INSERT.
|
||||
</p>
|
||||
<h3><a name="item4.11.3">4.11.3</a>) Nezpůsobí currval() a nextval() problémy ve více uživatelském prostředí?</h3>
|
||||
<p>Ne, currval vrací vždy hodnotu, která byla vygenerována pro vás.
|
||||
</p>
|
||||
<h3><a name="item4.11.4">4.11.4</a>) Proč není vygenerované číslo použito při přerušení transakce?Proč vznikají díry v číslování prostřednictvím sekvence nebo typu SERIAL?</h3>
|
||||
<p>Poté co sekvence vygeneruje nové číslo, tak se nedochází k zamčení sekvence a nečeká se na úspěšné nebo neúspěšné dokončení transakce. Odvoláním transakce, která si vyžádala čísla sekvence se tato čísla nenávratně ztratí.
|
||||
</p>
|
||||
<h3><a name="item4.12">4.12</a>) Co to je OID? Co je to CTID?</h3>
|
||||
<p>V případě, že tabulku nezaložíme s atributem WITHOUT OIDS, tak má každý řádek unikátní identifikační číslo OID. Toto číslo je 4 bajtové celé číslo, které je jedinečné v celé instalaci. Přeteče po 4 miliardách řádků. PostgreSQL používá OIDs jako interní linky v interních systémových tabulkách.
|
||||
</p>
|
||||
<p>K získání unikátního čísla v nesystémových tabulkách je vhodnější použití typu SERIAL než OID, jelikož sekvence SERIAL se používá pouze pro jednu tabulku a je tudíž méně náchylná na přetečení. Pokud byste se toho obávali, použijte typ SERIAL8.
|
||||
</p>
|
||||
<p>CTID se používá k identifikaci konkrétního fyzického řádku. CTID se mění pokud je řádek modifikován nebo znovu načten. Používají ho indexy jako adresaci fyzických řádků.
|
||||
</p>
|
||||
<h3><a name="item4.13">4.13</a>) Co znamená chybové hlášení "ERROR: Memory exhausted in AllocSetAlloc()"?</h3>
|
||||
<p>Pravděpodobně jste vyčerpal dostupnou virtuální paměť, nebo tvůj kernel
|
||||
má příliš nízké limity u určitých zdrojů. Před startem PostgreSQL vyzkoušejte:
|
||||
</p>
|
||||
<pre>
|
||||
ulimit -d 262144
|
||||
limit datasize 256m
|
||||
</pre><p>Možná, že se projde pouze jeden příkaz - záleží to na vašem shellu.
|
||||
Měl by zvednout limity datových segmentů vašich procesů na dostatečně velkou
|
||||
hodnotu a snad umožnit dokončení dotazu. Změna limitů se bude aplikovat
|
||||
pouze na aktuální proces a na všechny nově vytvořené procesy. Jestliže máte
|
||||
problém s SQL klientem, protože vám server vrátil příliš dat, zkuste to
|
||||
před startem klienta.
|
||||
</p>
|
||||
<h3><a name="item4.14">4.14</a>) Jak zjistím, kterou verzi PostgreSQL používám?</h3>
|
||||
<p>V psql napište:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT version();
|
||||
</pre>
|
||||
<h3><a name="item4.15">4.15</a>) Jak vytvořit sloupec, který bude implicitně obsahovat aktuální čas?</h3>
|
||||
<p>Použijte CURRENT_TIMESTAMP:
|
||||
</p>
|
||||
<pre>
|
||||
CREATE TABLE test (x int, modtime TIMESTAMP DEFAULT CURRENT_TIMESTAMP );
|
||||
</pre>
|
||||
<h3><a name="item4.16">4.16</a>) Jak provést vnější spojení (outer join)?</h3>
|
||||
<p>PostgreSQL podporuje standardní SQL syntaxi pro vnější spojení. Zde jsou
|
||||
dva příklady:
|
||||
</p>
|
||||
<pre>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 ON (t1.col = t2.col);
|
||||
</pre><p>nebo
|
||||
</p>
|
||||
<pre>
|
||||
SELECT *
|
||||
FROM t1 LEFT OUTER JOIN t2 USING (col);
|
||||
</pre><p>Tyto identické dotazy spojí sloupec t1.col k sloupci t2.col, a ještě vrátí všechny nespárované řádky t2 (ty, které nedohledá v t2). RIGHT JOIN by připojil všechny nespárované řádky z t2. FULL JOIN vrátí všechny spárované řádky i všechny zbývající řádky z obou tabulek. Klíčové slovo OUTER je volitelné. Běžná operace JOIN se také označuje jako vnitřní spojení.
|
||||
</p>
|
||||
<h3><a name="item4.17">4.17</a>) Jak provést dotaz napříč několika databázemi?</h3>
|
||||
<p>Neexistuje žádný způsob, jak se v dotazu odkazovat na tabulky z jiné než aktuální databáze. A to protože má systémové tabulky uložené nezávisle v každé databázi a není tak úplně zřejmé, jak by se dotaz provedený napříč databázemi měl chovat.
|
||||
</p>
|
||||
<p>Jeden z doplňků dblink umožňuje dotaz nad několika tabulkami pomocí funkcí. Druhý způsob je simultální připojení klienta ke všem relevantním databázím a sloučení výsledku na straně klienta.
|
||||
</p>
|
||||
<h3><a name="item4.18">4.18</a>) Může funkce vrátit více řádků nebo sloupců?</h3>
|
||||
<p>Jde to jednoduše pomocí set-returning funkce. Více na
|
||||
<a href="http://www.postgresql.org/docs/techdocs.17" title="http://www.postgresql.org/docs/techdocs.17">http://www.postgresql.org/docs/techdocs.17</a>.
|
||||
</p>
|
||||
<h3><a name="item4.19">4.19</a>) Co je příčinou chyby "relation with OID xxxxx does not exist"?</h3>
|
||||
<p>Nechtěným vedlejším efektem kešování SQL dotazů v PL/pgSQL funkci je problém s neplatnými odkazy na dočasné tabulky, které byly od prvního spuštění funkce zrušeny a znovu vytvořeny před dalším spuštěním PL/pgSQL funkce. Řešením je použít příkaz EXECUTE a to proto, že prováděcí plán SQL příkazu spouštěného příkazem EXECUTE se vytváří pokaždé znovu (neukládá se do cache).
|
||||
</p>
|
||||
<p>Tento problém by se neměl vyskytovat u PostgreSQL verze 8.3 a vyšších verzích.
|
||||
</p>
|
||||
<h3><a name="item4.20">4.20</a>) Jaké jsou možnosti replikace databází?</h3>
|
||||
<p>Replikaci databáze umožňuje několik technoligií. Každá má určité výhody a nevýhody.
|
||||
</p>
|
||||
<p>Master/Slave replikaci podporuje jeden hlavní server, který přijímá požadavky na zápis a čtení, a několik podřízených serverů, které umožňují pouze čtení (SELECT). Nejrozšířenějším volně dostupným řešením tohoto typu je <a href="http://main.slony.info/" title="http://main.slony.info/">Slony-I</a>.
|
||||
</p>
|
||||
<p>Replikace typu Multi-master podporuje existenci několika serverů s povoleným zápisem na více replikovaných serverech. Toto řešení zvyšuje zátěž serverů, protože je nutná synchronizace serverů. Nejrozšířenějším volně dostupným řešením je <a href="http://pgfoundry.org/projects/pgcluster/" title="http://pgfoundry.org/projects/pgcluster/">PGCluster</a>.
|
||||
</p>
|
||||
<p>Ještě existuje několik komerčních a hardware řešení replikací podporujících různé modely replikace.
|
||||
</p>
|
||||
<h3><a name="item4.21">4.21</a>) Proč v dotazu nejsou rozpoznány názvy mých tabulek nebo funkcí? Proč jsou velká písmena v názvech automaticky převedena na malá písmena?</h3>
|
||||
<p>Nejčastějším důvodem nerozpoznání názvu objektu bylo použití vložení názvu sloupce nebo tabulky mezi uvozovky při zakládání tabulky. Pokud se název zapíše mezi uvozovky, pak je case sensitive, a v důsledku toho je nutné názvy těchto sloupců nebo tabulek v SQL příkazech také vkládat mezi uvozovky (pokud obsahují velká písmena). Některé programy, jako je například pgAdmin, automaticky používají uvozovky. Takže pokud chcete, aby systém identifikoval identifikátor, musíte:
|
||||
</p>
|
||||
<ul><li> nepoužívat uvozovky v příkazu CREATE TABLE
|
||||
</li>
|
||||
<li> v identifikátoru použít pouze malá písmena
|
||||
</li>
|
||||
<li> v dotazech vkládat identifikátory do uvozovek
|
||||
</li>
|
||||
</ul>
|
||||
</body>
|
||||
</htm>
|
||||
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@ -1,4 +0,0 @@
|
||||
The FAQ* files in this directory are the master versions, and the
|
||||
../../FAQ* text files are created using lynx:
|
||||
|
||||
lynx -force_html -dont_wrap_pre -dump -hiddenlinks=ignore -nolist FAQ*
|
||||
Reference in New Issue
Block a user