<!--
doc/src/sgml/ref/create_extension.sgml
PostgreSQL documentation
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<refentry id="SQL-CREATEEXTENSION">
 <refmeta>
  <refentrytitle>CREATE EXTENSION</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>CREATE EXTENSION</refname>
  <refpurpose>install an extension</refpurpose>
 </refnamediv>

 <indexterm zone="sql-createextension">
  <primary>CREATE EXTENSION</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
CREATE EXTENSION <replaceable class="parameter">extension_name</replaceable>
    [ WITH ] [ SCHEMA [=] <replaceable class="parameter">schema</replaceable> ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>CREATE EXTENSION</command> loads a new extension into the current
   database.  There must not be an extension of the same name already loaded.
  </para>

  <para>
   Loading an extension essentially amounts to running the extension's script
   file.  The script will typically create new <acronym>SQL</> objects such as
   functions, data types, operators and index support methods.
   <command>CREATE EXTENSION</command> additionally records the identities
   of all the created objects, so that they can be dropped again if
   <command>DROP EXTENSION</command> is issued.
  </para>

  <para>
   For information about writing new extensions, see
   <xref linkend="extend-extensions">.
  </para>

  <para>
   Only superusers can execute <command>CREATE EXTENSION</command>.
  </para>

 </refsect1>

 <refsect1>
  <title>Parameters</title>

    <variablelist>
     <varlistentry>
      <term><replaceable class="parameter">extension_name</replaceable></term>
      <listitem>
       <para>
        The name of the extension to be
        installed. <productname>PostgreSQL</productname> will create the
        extension using details from the file
        <literal>SHAREDIR/contrib/</literal><replaceable class="parameter">extension</replaceable><literal>.control</literal>.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="parameter">schema</replaceable></term>
      <listitem>
       <para>
        The name of the schema in which to install the extension's
        objects, given that the extension allows its contents to be
        relocated.  The named schema must already exist.
        If not specified, and the extension's control file does not specify a
        schema either, the current default object creation schema is used.
       </para>
      </listitem>
     </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Install the <link linkend="hstore">hstore</link> extension into the
   current database:
<programlisting>
CREATE EXTENSION hstore;
</programlisting>
  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>CREATE EXTENSION</command> is a <productname>PostgreSQL</>
   extension.
  </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-alterextension"></member>
   <member><xref linkend="sql-dropextension"></member>
  </simplelist>
 </refsect1>

</refentry>
