mirror of
https://github.com/postgres/postgres.git
synced 2025-10-31 10:30:33 +03:00
202 lines
8.9 KiB
HTML
202 lines
8.9 KiB
HTML
<HTML>
|
|
<HEAD>
|
|
<TITLE>The POSTGRES95 User Manual - Introduction</TITLE>
|
|
</HEAD>
|
|
|
|
<BODY>
|
|
<font size=-1>
|
|
<A HREF="pg95user.html">[ TOC ]</A>
|
|
[ Previous ]
|
|
<A HREF="architec.html">[ Next ]</A>
|
|
</font>
|
|
<HR>
|
|
<H1>1. INTRODUCTION</H1>
|
|
<HR>
|
|
This document is the user manual for the
|
|
<A HREF="http://s2k-ftp.cs.berkeley.edu:8000/postgres95/"><B>POSTGRES95</B></A>
|
|
database management system developed at the University
|
|
of California at Berkeley. <B>POSTGRES95</B> is based on
|
|
<A HREF="http://s2k-ftp.CS.Berkeley.EDU:8000/postgres/postgres.html">
|
|
<B>POSTGRES release 4.2</B></A>. The POSTGRES project,
|
|
led by Professor Michael Stonebraker, has been sponsored by the
|
|
Defense Advanced Research Projects Agency (DARPA), the
|
|
Army Research Office (ARO), the National Science
|
|
Foundation (NSF), and ESL, Inc.
|
|
<H2>1.1. What is POSTGRES?</H2>
|
|
Traditional relational database management systems
|
|
(DBMSs) support a data model consisting of a collection
|
|
of named relations, containing attributes of a specific
|
|
type. In current commercial systems, possible types
|
|
include floating point numbers, integers, character
|
|
strings, money, and dates. It is commonly recognized
|
|
that this model is inadequate for future data
|
|
processing applications.
|
|
The relational model successfully replaced previous
|
|
models in part because of its "Spartan simplicity".
|
|
However, as mentioned, this simplicity often makes the
|
|
implementation of certain applications very difficult
|
|
to implement. POSTGRES offers substantial additional
|
|
power by incorporating the following four additional
|
|
basic constructs in such a way that users can easily
|
|
extend the system:
|
|
<p>
|
|
<PRE> classes
|
|
inheritance
|
|
types
|
|
functions
|
|
</PRE><p>
|
|
In addition, POSTGRES supports a powerful production
|
|
rule system.
|
|
|
|
<H2><A NAME="a-short-history-of-the-postgres-project">1.2. A Short History of the POSTGRES Project</A></H2>
|
|
Implementation of the POSTGRES DBMS began in 1986. The
|
|
initial concepts for the system were presented in
|
|
<A HREF="refs.html#STON86">[STON86]</A> and the definition of the initial data model
|
|
appeared in <A HREF="refs.html#ROW87">[ROWE87]</A>. The design of the rule system at
|
|
that time was described in <A HREF="refs.html#STON87a">[STON87a]</A>. The rationale
|
|
and architecture of the storage manager were detailed
|
|
in <A HREF="refs.html#STON87b">[STON87b]</A>.
|
|
POSTGRES has undergone several major releases since
|
|
then. The first "demoware" system became operational
|
|
in 1987 and was shown at the 1988 <B>ACM-SIGMOD</B>
|
|
Conference. We released Version 1, described in <A HREF="refs.html#STON90a">[STON90a]</A>,
|
|
to a few external users in June 1989. In response to a
|
|
critique of the first rule system <A HREF="refs.html#STON89">[STON89]</A>, the rule
|
|
system was redesigned <A HREF="refs.html#STON90">[STON90b]</A> and Version 2 was
|
|
released in June 1990 with the new rule system.
|
|
Version 3 appeared in 1991 and added support for multiple
|
|
storage managers, an improved query executor, and a
|
|
rewritten rewrite rule system. For the most part,
|
|
releases since then have focused on portability and
|
|
reliability.
|
|
POSTGRES has been used to implement many different
|
|
research and production applications. These include: a
|
|
financial data analysis system, a jet engine
|
|
performance monitoring package, an asteroid tracking
|
|
database, a medical information database, and several
|
|
geographic information systems. POSTGRES has also been
|
|
used as an educational tool at several universities.
|
|
Finally, <A HREF="http://www.illustra.com/">Illustra Information Technologies</A> picked up
|
|
the code and commercialized it.
|
|
POSTGRES became the primary data manager for the
|
|
<A HREF="http://www.sdsc.edu/0/Parts_Collabs/S2K/s2k_home.html">Sequoia 2000</A> scientific computing project in late 1992.
|
|
Furthermore, the size of the external user community
|
|
nearly doubled during 1993. It became increasingly
|
|
obvious that maintenance of the prototype code and
|
|
support was taking up large amounts of time that should
|
|
have been devoted to database research. In an effort
|
|
to reduce this support burden, the project officially
|
|
ended with <B>Version 4.2</B>.
|
|
|
|
<H2><A NAME="what-is-postgres95">1.3. What is <B>POSTGRES95</B>?</A></H2>
|
|
<B>POSTGRES95</B> is a derivative of the last official release
|
|
of POSTGRES (version 4.2). The code is now completely
|
|
ANSI C and the code size has been trimmed by 25%. There
|
|
are a lot of internal changes that improve performance
|
|
and code maintainability. <B>POSTGRES95</B> runs about 30-50%
|
|
faster on the Wisconsin Benchmark compared to v4.2.
|
|
Apart from bug fixes, these are the major enhancements:
|
|
<UL>
|
|
<LI>The query language <B>POSTQUEL</B> has been replaced with
|
|
<B>SQL</B> (implemented in the server). We do not support
|
|
subqueries (which can be imitated with user defined
|
|
<B>SQL</B> functions) at the moment. Aggregates have been
|
|
re-implemented. We also added support for <B>GROUP BY</B>.
|
|
The <B>libpq</B> interface is still available for <B>C</B>
|
|
programs.
|
|
<LI>In addition to the monitor program, we provide a new
|
|
program (<B>psql</B>) which supports <B>GNU</B> <B>readline</B>.
|
|
<LI>We added a new front-end library, <B>libpgtcl</B>, that
|
|
supports <B>Tcl</B>-based clients. A sample shell,
|
|
pgtclsh, provides new Tcl commands to interface <B>tcl</B>
|
|
programs with the <B>POSTGRES95</B> backend.
|
|
<LI>The large object interface has been overhauled. We
|
|
kept Inversion large objects as the only mechanism
|
|
for storing large objects. (This is not to be
|
|
confused with the Inversion file system which has been
|
|
removed.)
|
|
<LI>The instance-level rule system has been removed.
|
|
<LI>Rules are still available as rewrite rules.
|
|
<LI>A short tutorial introducing regular <B>SQL</B> features as
|
|
well as those of ours is distributed with the source
|
|
code.
|
|
<LI><B>GNU</B> make (instead of <B>BSD</B> make) is used for the
|
|
build. Also, <B>POSTGRES95</B> can be compiled with an
|
|
unpatched <B>gcc</B> (data alignment of doubles has been
|
|
fixed).
|
|
</UL>
|
|
<p>
|
|
<H2><A NAME="about-this-release">1.4. About This Release</A></H2>
|
|
<B>POSTGRES95</B> is available free of charge. This manual
|
|
describes version 1.0 of <B>POSTGRES95</B>. The authors have
|
|
compiled and tested <B>POSTGRES95</B> on the following
|
|
platforms:
|
|
<p>
|
|
<center>
|
|
<table border=4>
|
|
<tr>
|
|
<th>Architecture</th>
|
|
<th>Processor</th>
|
|
<th>Operating System</th>
|
|
</tr>
|
|
<tr>
|
|
<td>DECstation 3000</td>
|
|
<td>Alpha AXP</td>
|
|
<td>OSF/1 2.1, 3.0, 3.2</td>
|
|
</tr>
|
|
<tr>
|
|
<td>DECstation 5000</td>
|
|
<td>MIPS</td>
|
|
<td>ULTRIX 4.4</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Sun4</td>
|
|
<td>SPARC</td>
|
|
<td>SunOS 4.1.3, 4.1.3_U1; Solaris 2.4</td>
|
|
</tr>
|
|
<tr>
|
|
<td>H-P 9000/700 and 800</td>
|
|
<td>PA-RISC</td>
|
|
<td>HP-UX 9.00, 9.01, 9.03</td>
|
|
</tr>
|
|
<tr>
|
|
<td>Intel</td>
|
|
<td>X86</td>
|
|
<td>Linux 1.2.8, ELF</td>
|
|
</table>
|
|
</center>
|
|
<p>
|
|
<H2><A NAME="outline-of-this-manual">1.5. Outline of This Manual</A></H2>
|
|
From now on, We will use POSTGRES to mean <B>POSTGRES95</B>.
|
|
The first part of this manual goes over some basic sys-
|
|
tem concepts and procedures for starting the POSTGRES
|
|
system. We then turn to a tutorial overview of the
|
|
POSTGRES data model and SQL query language, introducing
|
|
a few of its advanced features. Next, we explain the
|
|
POSTGRES approach to extensibility and describe how
|
|
users can extend POSTGRES by adding user-defined types,
|
|
operators, aggregates, and both query language and pro-
|
|
gramming language functions. After an extremely brief
|
|
overview of the POSTGRES rule system, the manual
|
|
concludes with a detailed appendix that discusses some of
|
|
the more involved and operating system-specific
|
|
procedures involved in extending the system.
|
|
<HR>
|
|
<B>UNIX</B> is a trademark of X/Open, Ltd. Sun4, SPARC, SunOS
|
|
and Solaris are trademarks of Sun Microsystems, Inc. DEC,
|
|
DECstation, Alpha AXP and ULTRIX are trademarks of Digital
|
|
Equipment Corp. PA-RISC and HP-UX are trademarks of
|
|
Hewlett-Packard Co. OSF/1 is a trademark of the Open
|
|
Software Foundation.<p>
|
|
|
|
We assume proficiency with UNIX and C programming.
|
|
|
|
<HR>
|
|
<font size=-1>
|
|
<A HREF="pg95user.html">[ TOC ]</A>
|
|
[ Previous ]
|
|
<A HREF="architec.html">[ Next ]</A>
|
|
</font>
|
|
</BODY>
|
|
</HTML>
|