{"id":985,"date":"2016-06-19T08:50:12","date_gmt":"2016-06-19T15:50:12","guid":{"rendered":"https:\/\/database.guide\/?p=985"},"modified":"2020-11-16T14:02:18","modified_gmt":"2020-11-16T04:02:18","slug":"what-is-postgresql","status":"publish","type":"post","link":"https:\/\/database.guide\/what-is-postgresql\/","title":{"rendered":"What is PostgreSQL?"},"content":{"rendered":"<p><dfn>PostgreSQL<\/dfn> is an object-relational database management system (<a href=\"https:\/\/database.guide\/what-is-an-ordbms\/\">ORDBMS<\/a>). It is an open source system that is known for its close alignment with the SQL standard.<\/p>\n<p>PostgreSQL is one of the world&#8217;s most popular database management systems (<a href=\"https:\/\/database.guide\/what-is-a-dbms\/\">DBMS<\/a>), and it is consistently in the top 5 on the <a href=\"http:\/\/db-engines.com\/en\/ranking\">DB-Engines ranking list<\/a>.<\/p>\n<p><!--more--><\/p>\n<p>PostgreSQL is developed by the PostgreSQL Global Development Group, which includes\u00a0various companies and individuals.<\/p>\n<h2>PostgreSQL History<\/h2>\n<p>PostgreSQL started under the name\u00a0POSTGRES in 1986 at the University of California at Berkeley.\u00a0The\u00a0project was sponsored by the Defense Advanced Research Projects Agency (<acronym class=\"ACRONYM\">DARPA<\/acronym>), the Army Research Office (<acronym class=\"ACRONYM\">ARO<\/acronym>), the National Science Foundation (<acronym class=\"ACRONYM\">NSF<\/acronym>), and ESL, Inc.<\/p>\n<p>After several major releases\u00a0the\u00a0<span class=\"PRODUCTNAME\">POSTGRES<\/span> project officially ended in 1993 with Version 4.2.<\/p>\n<p>In 1994,\u00a0Postgres95 was released as an open-source descendant of the original <span class=\"PRODUCTNAME\">POSTGRES<\/span>\u00a0code. One of the changes was that\u00a0PostQUEL was replaced with <acronym class=\"ACRONYM\">SQL.<\/acronym><\/p>\n<p>In 1996, the name Postgres95 was changed to PostgreSQL, starting at version 6.0 in line with the sequence that had started with the original POSTGRES implementation.<\/p>\n<p>PostgreSQL has since become one of the most popular database management systems in the world.<\/p>\n<h2>PostgreSQL Features<\/h2>\n<p>PostgreSQL\u00a0comes with many\u00a0standard and advanced features, including:<\/p>\n<ul>\n<li>Fully ACID compliant<\/li>\n<li>Complex queries<\/li>\n<li>(Compound) <a href=\"https:\/\/database.guide\/what-is-a-primary-key\/\">primary keys<\/a><\/li>\n<li><a href=\"https:\/\/database.guide\/what-is-a-foreign-key\/\">Foreign keys<\/a> with restricting and cascading updates\/deletes,<\/li>\n<li>Check constraints, unique constraints, and not null constraints.<\/li>\n<li>Joins<\/li>\n<li><a href=\"https:\/\/database.guide\/what-is-a-view\/\">Views<\/a><\/li>\n<li>Triggers<\/li>\n<li><a href=\"https:\/\/database.guide\/what-is-a-stored-procedure\/\">Stored procedures<\/a> (in multiple languages -including Java, Perl, Python, Ruby, Tcl, C\/C++, and its own PL\/pgSQL)<\/li>\n<li>Table inheritance<\/li>\n<li>A\u00a0rule system (the <span class=\"emphasis\"><em>query rewrite system)<\/em><\/span>.<\/li>\n<li>Database events<\/li>\n<\/ul>\n<h2>Extensibility<\/h2>\n<p>Users can extend PostgreSQL by adding new:<\/p>\n<ul>\n<li>Data types<\/li>\n<li>Functions<\/li>\n<li>Operators<\/li>\n<li>Aggregate functions<\/li>\n<li>Index methods<\/li>\n<li>Procedural languages<\/li>\n<\/ul>\n<h2>Scalability<\/h2>\n<p>PostgreSQL is highly scalable. It can handle many concurrent users and it can hold a lot of data.\u00a0Here are some of the limits of PostgreSQL.<\/p>\n<table>\n<thead>\n<tr>\n<th>Limit<\/th>\n<th>Value<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Maximum <a href=\"https:\/\/database.guide\/what-is-a-database\/\">Database<\/a> Size<\/td>\n<td>Unlimited<\/td>\n<\/tr>\n<tr>\n<td>Maximum <a href=\"https:\/\/database.guide\/what-is-a-table\/\">Table<\/a> Size<\/td>\n<td>32 TB<\/td>\n<\/tr>\n<tr>\n<td>Maximum <a href=\"https:\/\/database.guide\/what-is-a-row\/\">Row<\/a> Size<\/td>\n<td>1.6 TB<\/td>\n<\/tr>\n<tr>\n<td>Maximum <a href=\"https:\/\/database.guide\/what-is-a-field\/\">Field<\/a> Size<\/td>\n<td>1 GB<\/td>\n<\/tr>\n<tr>\n<td>Maximum Rows per Table<\/td>\n<td>Unlimited<\/td>\n<\/tr>\n<tr>\n<td>Maximum <a href=\"https:\/\/database.guide\/what-is-a-column\/\">Columns<\/a> per Table<\/td>\n<td>250 &#8211; 1600 depending on column types<\/td>\n<\/tr>\n<tr>\n<td>Maximum Indexes per Table<\/td>\n<td>Unlimited<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Platforms<\/h2>\n<p>PostgreSQL is a cross platform DBMS and it runs on all major operating systems, including:<\/p>\n<ul>\n<li>Linux<\/li>\n<li>UNIX\n<ul>\n<li>AIX<\/li>\n<li>BSD<\/li>\n<li>HP-UX<\/li>\n<li>SGI IRIX<\/li>\n<li>Mac OS X<\/li>\n<li>Solaris, Tru64<\/li>\n<\/ul>\n<\/li>\n<li>Windows<\/li>\n<\/ul>\n<h2>PostgreSQL Admin Tools<\/h2>\n<p>There are many administration tools that can be used with PostgreSQL, many of which were built specifically for PostgreSQL.<\/p>\n<p>Some PostgreSQL distributions include administration tools along with the actual\u00a0PostgreSQL installation.<\/p>\n<p>Here are two:<\/p>\n<ul>\n<li><a href=\"http:\/\/www.enterprisedb.com\/products-services-training\/pgdownload#osx\">EnterpriseDB<\/a><\/li>\n<li><a href=\"http:\/\/www.bigsql.org\/postgresql\/installers.jsp\">BigSQL<\/a><\/li>\n<\/ul>\n<p>You can also download the admin tools separately. Here are three of the more popular ones:<\/p>\n<ul>\n<li><a href=\"https:\/\/www.pgadmin.org\/\">pgAdmin<\/a>.\u00a0Runs on\u00a0Linux, FreeBSD, Solaris, Mac OSX and Windows. Free.<\/li>\n<li><a href=\"http:\/\/phppgadmin.sourceforge.net\/doku.php\">phpPgAdmin<\/a>. Runs on Windows, Linux, Mac OSX, Unix any web server supporting PHP (any client with a web browser). Free.<\/li>\n<li><a href=\"http:\/\/www.aquafold.com\/aquadatastudio.html\">Aqua Data Studio<\/a>. Runs on many DBMSs. Runs on Windows, Linux, Mac OSX, Solaris, Java.\u00a0Costs\u00a0$499 USD per user.<\/li>\n<\/ul>\n<h2><\/h2>\n<h2>PostgreSQL Website<\/h2>\n<p>You can find out more information\u00a0about PostgreSQL\u00a0at the official <a href=\"https:\/\/www.postgresql.org\/\">PostgreSQL website<\/a>.<\/p>\n<h2><\/h2>\n","protected":false},"excerpt":{"rendered":"<p>PostgreSQL is an object-relational database management system (ORDBMS). It is an open source system that is known for its close alignment with the SQL standard. PostgreSQL is one of the world&#8217;s most popular database management systems (DBMS), and it is consistently in the top 5 on the DB-Engines ranking list.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[40],"tags":[35,20],"class_list":["post-985","post","type-post","status-publish","format-standard","hentry","category-postgresql","tag-dbms","tag-what-is"],"_links":{"self":[{"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/posts\/985","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/comments?post=985"}],"version-history":[{"count":4,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/posts\/985\/revisions"}],"predecessor-version":[{"id":11221,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/posts\/985\/revisions\/11221"}],"wp:attachment":[{"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/media?parent=985"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/categories?post=985"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/database.guide\/wp-json\/wp\/v2\/tags?post=985"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}