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1<?xml version="1.0" encoding="UTF-8" standalone="no"?>2<!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>CREATE EXTENSION</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="sql-createeventtrigger.html" title="CREATE EVENT TRIGGER" /><link rel="next" href="sql-createforeigndatawrapper.html" title="CREATE FOREIGN DATA WRAPPER" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">CREATE EXTENSION</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-createeventtrigger.html" title="CREATE EVENT TRIGGER">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-createforeigndatawrapper.html" title="CREATE FOREIGN DATA WRAPPER">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-CREATEEXTENSION"><div class="titlepage"></div><a id="id-1.9.3.64.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">CREATE EXTENSION</span></h2><p>CREATE EXTENSION — install an extension</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">3CREATE EXTENSION [ IF NOT EXISTS ] <em class="replaceable"><code>extension_name</code></em>4    [ WITH ] [ SCHEMA <em class="replaceable"><code>schema_name</code></em> ]5             [ VERSION <em class="replaceable"><code>version</code></em> ]6             [ CASCADE ]7</pre></div><div class="refsect1" id="id-1.9.3.64.5"><h2>Description</h2><p>8   <code class="command">CREATE EXTENSION</code> loads a new extension into the current9   database.  There must not be an extension of the same name already loaded.10  </p><p>11   Loading an extension essentially amounts to running the extension's script12   file.  The script will typically create new <acronym class="acronym">SQL</acronym> objects such as13   functions, data types, operators and index support methods.14   <code class="command">CREATE EXTENSION</code> additionally records the identities15   of all the created objects, so that they can be dropped again if16   <code class="command">DROP EXTENSION</code> is issued.17  </p><p>18   The user who runs <code class="command">CREATE EXTENSION</code> becomes the19   owner of the extension for purposes of later privilege checks, and20   normally also becomes the owner of any objects created by the21   extension's script.22  </p><p>23   Loading an extension ordinarily requires the same privileges that would24   be required to create its component objects.  For many extensions this25   means superuser privileges are needed.26   However, if the extension is marked <em class="firstterm">trusted</em> in27   its control file, then it can be installed by any user who has28   <code class="literal">CREATE</code> privilege on the current database.29   In this case the extension object itself will be owned by the calling30   user, but the contained objects will be owned by the bootstrap superuser31   (unless the extension's script explicitly assigns them to the calling32   user).  This configuration gives the calling user the right to drop the33   extension, but not to modify individual objects within it.34  </p></div><div class="refsect1" id="id-1.9.3.64.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">IF NOT EXISTS</code></span></dt><dd><p>35        Do not throw an error if an extension with the same name already36        exists.  A notice is issued in this case.  Note that there is no37        guarantee that the existing extension is anything like the one that38        would have been created from the currently-available script file.39       </p></dd><dt><span class="term"><em class="replaceable"><code>extension_name</code></em></span></dt><dd><p>40        The name of the extension to be41        installed. <span class="productname">PostgreSQL</span> will create the42        extension using details from the file43        <code class="literal">SHAREDIR/extension/</code><em class="replaceable"><code>extension_name</code></em><code class="literal">.control</code>.44       </p></dd><dt><span class="term"><em class="replaceable"><code>schema_name</code></em></span></dt><dd><p>45        The name of the schema in which to install the extension's46        objects, given that the extension allows its contents to be47        relocated.  The named schema must already exist.48        If not specified, and the extension's control file does not specify a49        schema either, the current default object creation schema is used.50       </p><p>51        If the extension specifies a <code class="literal">schema</code> parameter in its52        control file, then that schema cannot be overridden with53        a <code class="literal">SCHEMA</code> clause.  Normally, an error will be raised if54        a <code class="literal">SCHEMA</code> clause is given and it conflicts with the55        extension's <code class="literal">schema</code> parameter.  However, if56        the <code class="literal">CASCADE</code> clause is also given,57        then <em class="replaceable"><code>schema_name</code></em> is58        ignored when it conflicts.  The59        given <em class="replaceable"><code>schema_name</code></em> will be60        used for installation of any needed extensions that do not61        specify <code class="literal">schema</code> in their control files.62       </p><p>63        Remember that the extension itself is not considered to be within any64        schema: extensions have unqualified names that must be unique65        database-wide.  But objects belonging to the extension can be within66        schemas.67       </p></dd><dt><span class="term"><em class="replaceable"><code>version</code></em></span></dt><dd><p>68        The version of the extension to install.  This can be written as69        either an identifier or a string literal.  The default version is70        whatever is specified in the extension's control file.71       </p></dd><dt><span class="term"><code class="literal">CASCADE</code></span></dt><dd><p>72        Automatically install any extensions that this extension depends on73        that are not already installed.  Their dependencies are likewise74        automatically installed, recursively.  The <code class="literal">SCHEMA</code> clause,75        if given, applies to all extensions that get installed this way.76        Other options of the statement are not applied to77        automatically-installed extensions; in particular, their default78        versions are always selected.79       </p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.64.7"><h2>Notes</h2><p>80   Before you can use <code class="command">CREATE EXTENSION</code> to load an extension81   into a database, the extension's supporting files must be installed.82   Information about installing the extensions supplied with83   <span class="productname">PostgreSQL</span> can be found in84   <a class="link" href="contrib.html" title="Appendix F. Additional Supplied Modules and Extensions">Additional Supplied Modules</a>.85  </p><p>86   The extensions currently available for loading can be identified from the87   <a class="link" href="view-pg-available-extensions.html" title="54.2. pg_available_extensions"><code class="structname">pg_available_extensions</code></a>88   or89   <a class="link" href="view-pg-available-extension-versions.html" title="54.3. pg_available_extension_versions"><code class="structname">pg_available_extension_versions</code></a>90   system views.91  </p><div class="caution"><h3 class="title">Caution</h3><p>92    Installing an extension as superuser requires trusting that the93    extension's author wrote the extension installation script in a secure94    fashion.  It is not terribly difficult for a malicious user to create95    trojan-horse objects that will compromise later execution of a96    carelessly-written extension script, allowing that user to acquire97    superuser privileges.  However, trojan-horse objects are only hazardous98    if they are in the <code class="varname">search_path</code> during script99    execution, meaning that they are in the extension's installation target100    schema or in the schema of some extension it depends on.  Therefore, a101    good rule of thumb when dealing with extensions whose scripts have not102    been carefully vetted is to install them only into schemas for which103    CREATE privilege has not been and will not be granted to any untrusted104    users.  Likewise for any extensions they depend on.105   </p><p>106    The extensions supplied with <span class="productname">PostgreSQL</span> are107    believed to be secure against installation-time attacks of this sort,108    except for a few that depend on other extensions.  As stated in the109    documentation for those extensions, they should be installed into secure110    schemas, or installed into the same schemas as the extensions they111    depend on, or both.112   </p></div><p>113   For information about writing new extensions, see114   <a class="xref" href="extend-extensions.html" title="38.17. Packaging Related Objects into an Extension">Section 38.17</a>.115  </p></div><div class="refsect1" id="id-1.9.3.64.8"><h2>Examples</h2><p>116   Install the <a class="link" href="hstore.html" title="F.18. hstore — hstore key/value datatype">hstore</a> extension into the117   current database, placing its objects in schema <code class="literal">addons</code>:118</p><pre class="programlisting">119CREATE EXTENSION hstore SCHEMA addons;120</pre><p>121   Another way to accomplish the same thing:122</p><pre class="programlisting">123SET search_path = addons;124CREATE EXTENSION hstore;125</pre></div><div class="refsect1" id="id-1.9.3.64.9"><h2>Compatibility</h2><p>126   <code class="command">CREATE EXTENSION</code> is a <span class="productname">PostgreSQL</span>127   extension.128  </p></div><div class="refsect1" id="id-1.9.3.64.10"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-alterextension.html" title="ALTER EXTENSION"><span class="refentrytitle">ALTER EXTENSION</span></a>, <a class="xref" href="sql-dropextension.html" title="DROP EXTENSION"><span class="refentrytitle">DROP EXTENSION</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-createeventtrigger.html" title="CREATE EVENT TRIGGER">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-createforeigndatawrapper.html" title="CREATE FOREIGN DATA WRAPPER">Next</a></td></tr><tr><td width="40%" align="left" valign="top">CREATE EVENT TRIGGER </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 16.3 Documentation">Home</a></td><td width="40%" align="right" valign="top"> CREATE FOREIGN DATA WRAPPER</td></tr></table></div></body></html>