<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>1. What is PostgreSQL?</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="preface.html" title="Preface" /><link rel="next" href="history.html" title="2. A Brief History of PostgreSQL" /></head><body><div xmlns="http://www.w3.org/TR/xhtml1/transitional" class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">1. What is <span xmlns="http://www.w3.org/1999/xhtml" class="productname">PostgreSQL</span>?</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="preface.html" title="Preface">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="preface.html" title="Preface">Up</a></td><th width="60%" align="center">Preface</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 11.5 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="history.html" title="2. A Brief History of PostgreSQL">Next</a></td></tr></table><hr></hr></div><div class="sect1" id="INTRO-WHATIS"><div class="titlepage"><div><div><h2 class="title" style="clear: both">1. What is <span class="productname">PostgreSQL</span>?</h2></div></div></div><p> <span class="productname">PostgreSQL</span> is an object-relational database management system (<acronym class="acronym">ORDBMS</acronym>) based on <a class="ulink" href="http://db.cs.berkeley.edu/postgres.html" target="_top"> <span class="productname">POSTGRES, Version 4.2</span></a>, developed at the University of California at Berkeley Computer Science Department. POSTGRES pioneered many concepts that only became available in some commercial database systems much later. </p><p> <span class="productname">PostgreSQL</span> is an open-source descendant of this original Berkeley code. It supports a large part of the SQL standard and offers many modern features: </p><div class="itemizedlist"><ul class="itemizedlist compact" style="list-style-type: disc; "><li class="listitem">complex queries</li><li class="listitem">foreign keys</li><li class="listitem">triggers</li><li class="listitem">updatable views</li><li class="listitem">transactional integrity</li><li class="listitem">multiversion concurrency control</li></ul></div><p> Also, <span class="productname">PostgreSQL</span> can be extended by the user in many ways, for example by adding new </p><div class="itemizedlist"><ul class="itemizedlist compact" style="list-style-type: disc; "><li class="listitem">data types</li><li class="listitem">functions</li><li class="listitem">operators</li><li class="listitem">aggregate functions</li><li class="listitem">index methods</li><li class="listitem">procedural languages</li></ul></div><p> </p><p> And because of the liberal license, <span class="productname">PostgreSQL</span> can be used, modified, and distributed by anyone free of charge for any purpose, be it private, commercial, or academic. </p></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="preface.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="preface.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="history.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Preface </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> 2. A Brief History of <span class="productname">PostgreSQL</span></td></tr></table></div></body></html>
