<command>DROP EXTENSION</command> is issued.

</para>

<para>

For information about writing new extensions, see

<xref linkend="extend-extensions">.

</para>

<para>

Loading an extension requires the same privileges that would be

required to create its component objects. For most extensions this

Do not throw an error if an extension with the same name already

exists. A notice is issued in this case. Note that there is no

guarantee that the existing extension is anything like the one that

would have been created.

would have been created from the currently-available script file.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Notes</title>

<para>

Before you can use <command>CREATE EXTENSION</> to load an extension

into a database, the extension's supporting files must be installed.

Information about installing the extensions supplied with

<productname>PostgreSQL</productname> can be found in

<link linkend="contrib">Additional Supplied Modules</link>.

</para>

<para>

The extensions currently available for loading can be identified from the

<link linkend="view-pg-available-extensions"><structname>pg_available_extensions</structname></link>

or

<link linkend="view-pg-available-extension-versions"><structname>pg_available_extension_versions</structname></link>

system views.

</para>

<para>

For information about writing new extensions, see

<xref linkend="extend-extensions">.

</para>

</refsect1>

<refsect1>

<title>Examples</title>