doc/src/sgml/history.sgml

   1 <!-- doc/src/sgml/history.sgml -->
   2
   3 <sect1 id="history">
   4  <title>A Brief History of <productname>PostgreSQL</productname></title>
   5
   6  <indexterm zone="history">
   7   <primary>history</primary>
   8   <secondary>of PostgreSQL</secondary>
   9  </indexterm>
  10
  11  <para>
  12   The object-relational database management system now known as
  13   <productname>PostgreSQL</productname> is derived from the
  14   <productname>POSTGRES</productname> package written at the
  15   University of California at Berkeley.  With decades of
  16   development behind it, <productname>PostgreSQL</productname> is now
  17   the most advanced open-source database available anywhere.
  18  </para>
  19
  20  <para>
  21   Another take on the history presented here can be found in Dr. Joe
  22   Hellerstein's paper <quote>Looking Back at Postgres</quote>
  23   <xref linkend="hell18"/>.
  24  </para>
  25
  26  <sect2 id="history-berkeley">
  27   <title>The Berkeley <productname>POSTGRES</productname> Project</title>
  28
  29   <indexterm zone="history-berkeley">
  30    <primary>POSTGRES</primary>
  31   </indexterm>
  32
  33   <para>
  34    The <productname>POSTGRES</productname> project, led by Professor
  35    Michael Stonebraker, was sponsored by the Defense Advanced Research
  36    Projects Agency (<acronym>DARPA</acronym>), the Army Research
  37    Office (<acronym>ARO</acronym>), the National Science Foundation
  38    (<acronym>NSF</acronym>), and ESL, Inc.  The implementation of
  39    <productname>POSTGRES</productname> began in 1986.  The initial
  40    concepts for the system were presented in <xref linkend="ston86"/>,
  41    and the definition of the initial data model appeared in <xref
  42    linkend="rowe87"/>.  The design of the rule system at that time was
  43    described in <xref linkend="ston87a"/>.  The rationale and
  44    architecture of the storage manager were detailed in <xref
  45    linkend="ston87b"/>.
  46   </para>
  47
  48   <para>
  49    <productname>POSTGRES</productname> has undergone several major
  50    releases since then.  The first <quote>demoware</quote> system
  51    became operational in 1987 and was shown at the 1988
  52    <acronym>ACM-SIGMOD</acronym> Conference.  Version 1, described in
  53    <xref linkend="ston90a"/>, was released to a few external users in
  54    June 1989.  In response to a critique of the first rule system
  55    (<xref linkend="ston89"/>), the rule system was redesigned (<xref
  56    linkend="ston90b"/>), and Version 2 was released in June 1990 with
  57    the new rule system.  Version 3 appeared in 1991 and added support
  58    for multiple storage managers, an improved query executor, and a
  59    rewritten rule system.  For the most part, subsequent releases
  60    until <productname>Postgres95</productname> (see below) focused on
  61    portability and reliability.
  62   </para>
  63
  64   <para>
  65    <productname>POSTGRES</productname> has been used to implement many
  66    different research and production applications.  These include: a
  67    financial data analysis system, a jet engine performance monitoring
  68    package, an asteroid tracking database, a medical information
  69    database, and several geographic information systems.
  70    <productname>POSTGRES</productname> has also been used as an
  71    educational tool at several universities.  Finally, Illustra
  72    Information Technologies (later merged into
  73    <ulink url="https://www.ibm.com/analytics/informix"><productname>Informix</productname></ulink>,
  74    which is now owned by <ulink
  75    url="https://www.ibm.com/">IBM</ulink>) picked up the code and
  76    commercialized it.  In late 1992,
  77    <productname>POSTGRES</productname> became the primary data manager
  78    for the
  79    <ulink url="http://meteora.ucsd.edu/s2k/s2k_home.html">
  80    Sequoia 2000 scientific computing project</ulink>.
  81   </para>
  82
  83   <para>
  84    The size of the external user community nearly doubled during 1993.
  85    It became increasingly obvious that maintenance of the prototype
  86    code and support was taking up large amounts of time that should
  87    have been devoted to database research.  In an effort to reduce
  88    this support burden, the Berkeley
  89    <productname>POSTGRES</productname> project officially ended with
  90    Version 4.2.
  91   </para>
  92  </sect2>
  93
  94  <sect2 id="history-postgres95">
  95   <title><productname>Postgres95</productname></title>
  96
  97   <indexterm zone="history-postgres95">
  98    <primary>Postgres95</primary>
  99   </indexterm>
 100
 101   <para>
 102    In 1994, Andrew Yu and Jolly Chen added an SQL language interpreter
 103    to <productname>POSTGRES</productname>.  Under a new name,
 104    <productname>Postgres95</productname> was subsequently released to
 105    the web to find its own way in the world as an open-source
 106    descendant of the original <productname>POSTGRES</productname>
 107    Berkeley code.
 108   </para>
 109
 110   <para>
 111    <productname>Postgres95</productname> code was completely ANSI C
 112    and trimmed in size by 25%. Many internal changes improved
 113    performance and
 114    maintainability. <productname>Postgres95</productname> release
 115    1.0.x ran about 30&ndash;50% faster on the Wisconsin Benchmark compared
 116    to <productname>POSTGRES</productname>, Version 4.2.  Apart from
 117    bug fixes, the following were the major enhancements:
 118
 119    <itemizedlist>
 120     <listitem>
 121      <para>
 122       The query language PostQUEL was replaced with
 123       <acronym>SQL</acronym> (implemented in the server).  (Interface
 124       library <link linkend="libpq">libpq</link> was named after PostQUEL.)
 125       Subqueries
 126       were not supported until <productname>PostgreSQL</productname>
 127       (see below), but they could be imitated in
 128       <productname>Postgres95</productname> with user-defined
 129       <acronym>SQL</acronym> functions. Aggregate functions were
 130       re-implemented.  Support for the <literal>GROUP BY</literal>
 131       query clause was also added.
 132      </para>
 133     </listitem>
 134
 135     <listitem>
 136      <para>
 137       A new program
 138       (<application>psql</application>) was provided for interactive
 139       SQL queries, which used <acronym>GNU</acronym>
 140       <application>Readline</application>.  This largely superseded
 141       the old <application>monitor</application> program.
 142      </para>
 143     </listitem>
 144
 145     <listitem>
 146      <para>
 147       A new front-end library, <filename>libpgtcl</filename>,
 148       supported <acronym>Tcl</acronym>-based clients.  A sample shell,
 149       <command>pgtclsh</command>, provided new Tcl commands to
 150       interface <application>Tcl</application> programs with the
 151       <productname>Postgres95</productname> server.
 152      </para>
 153     </listitem>
 154
 155     <listitem>
 156      <para>
 157       The large-object interface was overhauled. The inversion large
 158       objects were the only mechanism for storing large objects.  (The
 159       inversion file system was removed.)
 160      </para>
 161     </listitem>
 162
 163     <listitem>
 164      <para>
 165       The instance-level rule system was removed.  Rules were still
 166       available as rewrite rules.
 167      </para>
 168     </listitem>
 169
 170     <listitem>
 171      <para>
 172       A short tutorial introducing regular <acronym>SQL</acronym>
 173       features as well as those of
 174       <productname>Postgres95</productname> was distributed with the
 175       source code
 176      </para>
 177     </listitem>
 178
 179     <listitem>
 180      <para>
 181       <acronym>GNU</acronym> make (instead of <acronym>BSD</acronym>
 182       make) was used for the build.  Also,
 183       <productname>Postgres95</productname> could be compiled with an
 184       unpatched <productname>GCC</productname> (data alignment of
 185       doubles was fixed).
 186      </para>
 187     </listitem>
 188    </itemizedlist>
 189   </para>
 190  </sect2>
 191
 192  <sect2 id="history-postgresql">
 193   <title><productname>PostgreSQL</productname></title>
 194
 195   <para>
 196    By 1996, it became clear that the name <quote>Postgres95</quote>
 197    would not stand the test of time. We chose a new name,
 198    <productname>PostgreSQL</productname>, to reflect the relationship
 199    between the original <productname>POSTGRES</productname> and the
 200    more recent versions with <acronym>SQL</acronym> capability.  At
 201    the same time, we set the version numbering to start at 6.0,
 202    putting the numbers back into the sequence originally begun by the
 203    Berkeley <productname>POSTGRES</productname> project.
 204   </para>
 205
 206   <para>
 207    Many people continue to refer to
 208    <productname>PostgreSQL</productname> as <quote>Postgres</quote>
 209    (now rarely in all capital letters) because of tradition or because
 210    it is easier to pronounce.  This usage is widely accepted as a
 211    nickname or alias.
 212   </para>
 213
 214   <para>
 215    The emphasis during development of
 216    <productname>Postgres95</productname> was on identifying and
 217    understanding existing problems in the server code.  With
 218    <productname>PostgreSQL</productname>, the emphasis has shifted to
 219    augmenting features and capabilities, although work continues in
 220    all areas.
 221   </para>
 222
 223   <para>
 224    Details about what has happened in
 225    each <productname>PostgreSQL</productname> release since then
 226    can be found at
 227    <ulink url="https://www.postgresql.org/docs/release/">https://www.postgresql.org/docs/release/</ulink>.
 228   </para>
 229  </sect2>
 230 </sect1>