<!-- doc/src/sgml/history.sgml -->

<sect1 id="history">
 <title>A Brief History of <productname>PostgreSQL</productname></title>

 <indexterm zone="history">
  <primary>history</primary>
  <secondary>of PostgreSQL</secondary>
 </indexterm>

 <para>
  The object-relational database management system now known as
  <productname>PostgreSQL</productname> is derived from the
  <productname>POSTGRES</productname> package written at the
  University of California at Berkeley.  With decades of
  development behind it, <productname>PostgreSQL</productname> is now
  the most advanced open-source database available anywhere.
 </para>

 <para>
  Another take on the history presented here can be found in Dr. Joe
  Hellerstein's paper <quote>Looking Back at Postgres</quote>
  <xref linkend="hell18"/>.
 </para>

 <sect2 id="history-berkeley">
  <title>The Berkeley <productname>POSTGRES</productname> Project</title>

  <indexterm zone="history-berkeley">
   <primary>POSTGRES</primary>
  </indexterm>

  <para>
   The <productname>POSTGRES</productname> project, led by Professor
   Michael Stonebraker, was sponsored by the Defense Advanced Research
   Projects Agency (<acronym>DARPA</acronym>), the Army Research
   Office (<acronym>ARO</acronym>), the National Science Foundation
   (<acronym>NSF</acronym>), and ESL, Inc.  The implementation of
   <productname>POSTGRES</productname> began in 1986.  The initial
   concepts for the system were presented in <xref linkend="ston86"/>,
   and the definition of the initial data model appeared in <xref
   linkend="rowe87"/>.  The design of the rule system at that time was
   described in <xref linkend="ston87a"/>.  The rationale and
   architecture of the storage manager were detailed in <xref
   linkend="ston87b"/>.
  </para>

  <para>
   <productname>POSTGRES</productname> has undergone several major
   releases since then.  The first <quote>demoware</quote> system
   became operational in 1987 and was shown at the 1988
   <acronym>ACM-SIGMOD</acronym> Conference.  Version 1, described in
   <xref linkend="ston90a"/>, was released to a few external users in
   June 1989.  In response to a critique of the first rule system
   (<xref linkend="ston89"/>), the rule system was redesigned (<xref
   linkend="ston90b"/>), 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 rule system.  For the most part, subsequent releases
   until <productname>Postgres95</productname> (see below) focused on
   portability and reliability.
  </para>

  <para>
   <productname>POSTGRES</productname> 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.
   <productname>POSTGRES</productname> has also been used as an
   educational tool at several universities.  Finally, Illustra
   Information Technologies (later merged into
   <ulink url="https://www.ibm.com/analytics/informix"><productname>Informix</productname></ulink>,
   which is now owned by <ulink
   url="https://www.ibm.com/">IBM</ulink>) picked up the code and
   commercialized it.  In late 1992,
   <productname>POSTGRES</productname> became the primary data manager
   for the Sequoia 2000 scientific computing project described in
   <xref linkend="ston92"/>.
  </para>

  <para>
   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 Berkeley
   <productname>POSTGRES</productname> project officially ended with
   Version 4.2.
  </para>
 </sect2>

 <sect2