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Make the CREATE TABLE ref page more readable and update some information.

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This commit is contained in:
Peter Eisentraut
2001-10-22 18:14:47 +00:00
parent e97fe98c36
commit f08c9ff84b
5 changed files with 865 additions and 2143 deletions
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16
doc/src/sgml/ref/alter_table.sgml
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@@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.29 2001/10/12 00:07:14 tgl Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.30 2001/10/22 18:14:47 petere Exp $
Postgres documentation
-->
@@ -161,15 +161,14 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
<para>
<command>ALTER TABLE</command> changes the definition of an existing table.
The <literal>ADD COLUMN</literal> form adds a new column to the table
using the same syntax as <xref linkend="SQL-CREATETABLE"
endterm="SQL-CREATETABLE-title">.
using the same syntax as <xref linkend="SQL-CREATETABLE">.
The <literal>ALTER COLUMN SET/DROP DEFAULT</literal> forms
allow you to set or remove the default for the column. Note that defaults
only apply to subsequent <command>INSERT</command> commands; they do not
cause rows already in the table to change.
The <literal>ALTER COLUMN SET STATISTICS</literal> form allows you to
set the statistics-gathering target for subsequent
<xref linkend="sql-analyze" endterm="sql-analyze-title"> operations.
<xref linkend="sql-analyze"> operations.
The <literal>RENAME</literal> clause causes the name of a table or column
to change without changing any of the data contained in
the affected table. Thus, the table or column will
@@ -177,7 +176,7 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
executed.
The ADD <replaceable class="PARAMETER">table constraint definition</replaceable> clause
adds a new constraint to the table using the same syntax as <xref
linkend="SQL-CREATETABLE" endterm="SQL-CREATETABLE-title">.
linkend="SQL-CREATETABLE">.
The DROP CONSTRAINT <replaceable class="PARAMETER">constraint</replaceable> clause
drops all CHECK constraints on the table (and its children) that match <replaceable class="PARAMETER">constraint</replaceable>.
The OWNER clause changes the owner of the table to the user <replaceable class="PARAMETER">
@@ -205,18 +204,17 @@ ALTER TABLE <replaceable class="PARAMETER">table</replaceable>
You can use the <literal>SET DEFAULT</literal> form
of <command>ALTER TABLE</command> to set the default later.
(You may also want to update the already existing rows to the
new default value, using <xref linkend="sql-update"
endterm="sql-update-title">.)
new default value, using <xref linkend="sql-update">.)
</para>
<para>
Currently only CHECK constraints can be dropped from a table. The RESTRICT
keyword is required, although dependencies are not checked. The CASCADE
option is unsupported. To remove a PRIMARY or UNIQUE constraint, drop the
relevant index using the <xref linkend="SQL-DROPINDEX" endterm="SQL-DROPINDEX-TITLE"> command.
relevant index using the <xref linkend="SQL-DROPINDEX"> command.
To remove FOREIGN KEY constraints you need to recreate
and reload the table, using other parameters to the
<xref linkend="SQL-CREATETABLE" endterm="SQL-CREATETABLE-title">
<xref linkend="SQL-CREATETABLE">
command.
</para>
<para>