doc/src/sgml/history.sgml

   1 <!-- $PostgreSQL$ -->
   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 over two decades of
  16   development behind it, <productname>PostgreSQL</productname> is now
  17   the most advanced open-source database available anywhere.
  18  </para>
  19
  20  <sect2 id="history-berkeley">
  21   <title>The Berkeley <productname>POSTGRES</productname> Project</title>
  22
  23   <indexterm zone="history-berkeley">
  24    <primary>POSTGRES</primary>
  25   </indexterm>
  26
  27   <para>
  28    The <productname>POSTGRES</productname> project, led by Professor
  29    Michael Stonebraker, was sponsored by the Defense Advanced Research
  30    Projects Agency (<acronym>DARPA</acronym>), the Army Research
  31    Office (<acronym>ARO</acronym>), the National Science Foundation
  32    (<acronym>NSF</acronym>), and ESL, Inc.  The implementation of
  33    <productname>POSTGRES</productname> began in 1986.  The initial
  34    concepts for the system were presented in <xref linkend="STON86">,
  35    and the definition of the initial data model appeared in <xref
  36    linkend="ROWE87">.  The design of the rule system at that time was
  37    described in <xref linkend="STON87a">.  The rationale and
  38    architecture of the storage manager were detailed in <xref
  39    linkend="STON87b">.
  40   </para>
  41
  42   <para>
  43    <productname>POSTGRES</productname> has undergone several major
  44    releases since then.  The first <quote>demoware</quote> system
  45    became operational in 1987 and was shown at the 1988
  46    <acronym>ACM-SIGMOD</acronym> Conference.  Version 1, described in
  47    <xref linkend="STON90a">, was released to a few external users in
  48    June 1989.  In response to a critique of the first rule system
  49    (<xref linkend="STON89">), the rule system was redesigned (<xref
  50    linkend="STON90b">), and Version 2 was released in June 1990 with
  51    the new rule system.  Version 3 appeared in 1991 and added support
  52    for multiple storage managers, an improved query executor, and a
  53    rewritten rule system.  For the most part, subsequent releases
  54    until <productname>Postgres95</productname> (see below) focused on
  55    portability and reliability.
  56   </para>
  57
  58   <para>
  59    <productname>POSTGRES</productname> has been used to implement many
  60    different research and production applications.  These include: a
  61    financial data analysis system, a jet engine performance monitoring
  62    package, an asteroid tracking database, a medical information
  63    database, and several geographic information systems.
  64    <productname>POSTGRES</productname> has also been used as an
  65    educational tool at several universities.  Finally, Illustra
  66    Information Technologies (later merged into
  67    <ulink url="http://www.informix.com/"><productname>Informix</productname></ulink>,
  68    which is now owned by <ulink
  69    url="http://www.ibm.com/">IBM</ulink>) picked up the code and
  70    commercialized it.  In late 1992,
  71    <productname>POSTGRES</productname> became the primary data manager
  72    for the
  73    <ulink url="http://meteora.ucsd.edu/s2k/s2k_home.html">
  74    Sequoia 2000 scientific computing project</ulink>.
  75   </para>
  76
  77   <para>
  78    The size of the external user community nearly doubled during 1993.
  79    It became increasingly obvious that maintenance of the prototype
  80    code and support was taking up large amounts of time that should
  81    have been devoted to database research.  In an effort to reduce
  82    this support burden, the Berkeley
  83    <productname>POSTGRES</productname> project officially ended with
  84    Version 4.2.
  85   </para>
  86  </sect2>
  87
  88  <sect2 id="history-postgres95">
  89   <title><productname>Postgres95</productname></title>
  90
  91   <indexterm zone="history-postgres95">
  92    <primary>Postgres95</primary>
  93   </indexterm>
  94
  95   <para>
  96    In 1994, Andrew Yu and Jolly Chen added an SQL language interpreter
  97    to <productname>POSTGRES</productname>.  Under a new name,
  98    <productname>Postgres95</productname> was subsequently released to
  99    the web to find its own way in the world as an open-source
 100    descendant of the original <productname>POSTGRES</productname>
 101    Berkeley code.
 102   </para>
 103
 104   <para>
 105    <productname>Postgres95</productname> code was completely ANSI C
 106    and trimmed in size by 25%. Many internal changes improved
 107    performance and
 108    maintainability. <productname>Postgres95</productname> release
 109    1.0.x ran about 30-50% faster on the Wisconsin Benchmark compared
 110    to <productname>POSTGRES</productname>, Version 4.2.  Apart from
 111    bug fixes, the following were the major enhancements:
 112
 113    <itemizedlist>
 114     <listitem>
 115      <para>
 116       The query language PostQUEL was replaced with
 117       <acronym>SQL</acronym> (implemented in the server).  Subqueries
 118       were not supported until <productname>PostgreSQL</productname>
 119       (see below), but they could be imitated in
 120       <productname>Postgres95</productname> with user-defined
 121       <acronym>SQL</acronym> functions. Aggregate functions were
 122       re-implemented.  Support for the <literal>GROUP BY</literal>
 123       query clause was also added.
 124      </para>
 125     </listitem>
 126
 127     <listitem>
 128      <para>
 129       A new program
 130       (<application>psql</application>) was provided for interactive
 131       SQL queries, which used <acronym>GNU</acronym>
 132       <application>Readline</application>.  This largely superseded
 133       the old <application>monitor</> program.
 134      </para>
 135     </listitem>
 136
 137     <listitem>
 138      <para>
 139       A new front-end library, <filename>libpgtcl</filename>,
 140       supported <acronym>Tcl</acronym>-based clients.  A sample shell,
 141       <command>pgtclsh</command>, provided new Tcl commands to
 142       interface <application>Tcl</application> programs with the
 143       <productname>Postgres95</productname> server.
 144      </para>
 145     </listitem>
 146
 147     <listitem>
 148      <para>
 149       The large-object interface was overhauled. The inversion large
 150       objects were the only mechanism for storing large objects.  (The
 151       inversion file system was removed.)
 152      </para>
 153     </listitem>
 154
 155     <listitem>
 156      <para>
 157       The instance-level rule system was removed.  Rules were still
 158       available as rewrite rules.
 159      </para>
 160     </listitem>
 161
 162     <listitem>
 163      <para>
 164       A short tutorial introducing regular <acronym>SQL</acronym>
 165       features as well as those of
 166       <productname>Postgres95</productname> was distributed with the
 167       source code
 168      </para>
 169     </listitem>
 170
 171     <listitem>
 172      <para>
 173       <acronym>GNU</acronym> make (instead of <acronym>BSD</acronym>
 174       make) was used for the build.  Also,
 175       <productname>Postgres95</productname> could be compiled with an
 176       unpatched <productname>GCC</productname> (data alignment of
 177       doubles was fixed).
 178      </para>
 179     </listitem>
 180    </itemizedlist>
 181   </para>
 182  </sect2>
 183
 184  <sect2>
 185   <title><productname>PostgreSQL</productname></title>
 186
 187   <para>
 188    By 1996, it became clear that the name <quote>Postgres95</quote>
 189    would not stand the test of time. We chose a new name,
 190    <productname>PostgreSQL</productname>, to reflect the relationship
 191    between the original <productname>POSTGRES</productname> and the
 192    more recent versions with <acronym>SQL</acronym> capability.  At
 193    the same time, we set the version numbering to start at 6.0,
 194    putting the numbers back into the sequence originally begun by the
 195    Berkeley <productname>POSTGRES</productname> project.
 196   </para>
 197
 198   <para>
 199    Many people continue to refer to
 200    <productname>PostgreSQL</productname> as <quote>Postgres</quote>
 201    (now rarely in all capital letters) because of tradition or because
 202    it is easier to pronounce.  This usage is widely accepted as a
 203    nickname or alias.
 204   </para>
 205
 206   <para>
 207    The emphasis during development of
 208    <productname>Postgres95</productname> was on identifying and
 209    understanding existing problems in the server code.  With
 210    <productname>PostgreSQL</productname>, the emphasis has shifted to
 211    augmenting features and capabilities, although work continues in
 212    all areas.
 213   </para>
 214
 215   <para>
 216    Details about what has happened in <productname>PostgreSQL</> since
 217    then can be found in <xref linkend="release">.
 218   </para>
 219  </sect2>
 220 </sect1>