8593e1ff09
Multiple intros cause trouble since they have some section elements (e.g. "y2k.sgml") in common leading to duplicate labels. Include emacs formatting hints in the intro*.sgml sources.
97 lines
3.3 KiB
Plaintext
97 lines
3.3 KiB
Plaintext
<chapter id="intro">
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<title>Introduction</title>
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<para>
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This document is the user manual for the
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<ulink url="http://postgresql.org/"><productname>PostgreSQL</productname></ulink>
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database management system, originally developed at the University
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of California at Berkeley.
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<productname>PostgreSQL</productname> is based on
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<ulink url="http://s2k-ftp.CS.Berkeley.EDU:8000/postgres/postgres.html">
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<productname>Postgres release 4.2</productname></ulink>.
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The <productname>Postgres</productname> project,
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led by Professor Michael Stonebraker, was sponsored by the
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Defense Advanced Research Projects Agency (<acronym>DARPA</acronym>), the
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Army Research Office (<acronym>ARO</acronym>), the National Science
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Foundation (<acronym>NSF</acronym>), and ESL, Inc.
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</para>
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<sect1>
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<title> What is <productname>Postgres</productname>?</title>
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<para>
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Traditional relational database management systems
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(DBMSs) support a data model consisting of a collection
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of named relations, containing attributes of a specific
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type. In current commercial systems, possible types
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include floating point numbers, integers, character
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strings, money, and dates. It is commonly recognized
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that this model is inadequate for future data
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processing applications.
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The relational model successfully replaced previous
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models in part because of its "Spartan simplicity".
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However, as mentioned, this simplicity often makes the
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implementation of certain applications very difficult.
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<productname>Postgres</productname> offers substantial additional
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power by incorporating the following four additional
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basic concepts in such a way that users can easily
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extend the system:
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<simplelist>
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<member>classes</member>
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<member>inheritance</member>
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<member>types</member>
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<member>functions</member>
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</simplelist>
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</para>
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<para>
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Other features provide additional power and flexibility:
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<simplelist>
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<member>constraints</member>
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<member>triggers</member>
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<member>rules</member>
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<member>transaction integrity</member>
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</simplelist>
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</para>
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<para>
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These features put <productname>Postgres</productname> into the category of databases
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referred to as <firstterm>object-relational</firstterm>. Note that this is distinct
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from those referred to as <firstterm>object-oriented</firstterm>, which in general
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are not as well suited to supporting the traditional relational database languages.
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So, although <productname>Postgres</productname> has some object-oriented features,
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it is firmly in the relational database world. In fact, some commercial databases
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have recently incorporated features pioneered by <productname>Postgres</productname>.
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</para>
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</sect1>
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&history;
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&about;
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&info;
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¬ation;
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&y2k;
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&legal;
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</chapter>
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