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CREATE EXTENSION(7)	PostgreSQL 9.6.24 Documentation	   CREATE EXTENSION(7)

       CREATE_EXTENSION	- install an extension

       CREATE EXTENSION	[ IF NOT EXISTS	] extension_name
	   [ WITH ] [ SCHEMA schema_name ]
		    [ VERSION version ]
		    [ FROM old_version ]
		    [ CASCADE ]

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

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

       Loading an extension requires the same privileges that would be
       required	to create its component	objects. For most extensions this
       means superuser or database owner privileges are	needed.	The user who
       runs CREATE EXTENSION becomes the owner of the extension	for purposes
       of later	privilege checks, as well as the owner of any objects created
       by the extension's script.

	   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 from	the currently-available	script file.

	   The name of the extension to	be installed.  PostgreSQL will create
	   the extension using details from the	file

	   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.

	   If the extension specifies a	schema parameter in its	control	file,
	   then	that schema cannot be overridden with a	SCHEMA clause.
	   Normally, an	error will be raised if	a SCHEMA clause	is given and
	   it conflicts	with the extension's schema parameter. However,	if the
	   CASCADE clause is also given, then schema_name is ignored when it
	   conflicts. The given	schema_name will be used for installation of
	   any needed extensions that do not specify schema in their control

	   Remember that the extension itself is not considered	to be within
	   any schema: extensions have unqualified names that must be unique
	   database-wide. But objects belonging	to the extension can be	within

	   The version of the extension	to install. This can be	written	as
	   either an identifier	or a string literal. The default version is
	   whatever is specified in the	extension's control file.

	   FROM	old_version must be specified when, and	only when, you are
	   attempting to install an extension that replaces an "old style"
	   module that is just a collection of objects not packaged into an
	   extension. This option causes CREATE	EXTENSION to run an
	   alternative installation script that	absorbs	the existing objects
	   into	the extension, instead of creating new objects.	Be careful
	   that	SCHEMA specifies the schema containing these pre-existing

	   The value to	use for	old_version is determined by the extension's
	   author, and might vary if there is more than	one version of the
	   old-style module that can be	upgraded into an extension. For	the
	   standard additional modules supplied	with pre-9.1 PostgreSQL, use
	   unpackaged for old_version when updating a module to	extension

	   Automatically install any extensions	that this extension depends on
	   that	are not	already	installed. Their dependencies are likewise
	   automatically installed, recursively. The SCHEMA clause, if given,
	   applies to all extensions that get installed	this way. Other
	   options of the statement are	not applied to automatically-installed
	   extensions; in particular, their default versions are always

       Before you can use CREATE EXTENSION to load an extension	into a
       database, the extension's supporting files must be installed.
       Information about installing the	extensions supplied with PostgreSQL
       can be found in Additional Supplied Modules.

       The extensions currently	available for loading can be identified	from
       the pg_available_extensions or pg_available_extension_versions system

	   Installing an extension as superuser	requires trusting that the
	   extension's author wrote the	extension installation script in a
	   secure fashion. It is not terribly difficult	for a malicious	user
	   to create trojan-horse objects that will compromise later execution
	   of a	carelessly-written extension script, allowing that user	to
	   acquire superuser privileges. However, trojan-horse objects are
	   only	hazardous if they are in the search_path during	script
	   execution, meaning that they	are in the extension's installation
	   target schema or in the schema of some extension it depends on.
	   Therefore, a	good rule of thumb when	dealing	with extensions	whose
	   scripts have	not been carefully vetted is to	install	them only into
	   schemas for which CREATE privilege has not been and will not	be
	   granted to any untrusted users. Likewise for	any extensions they
	   depend on.

	   The extensions supplied with	PostgreSQL are believed	to be secure
	   against installation-time attacks of	this sort, except for a	few
	   that	depend on other	extensions. As stated in the documentation for
	   those extensions, they should be installed into secure schemas, or
	   installed into the same schemas as the extensions they depend on,
	   or both.

       For information about writing new extensions, see Section 36.15,
       "Packaging Related Objects into an Extension", in the documentation.

       Install the hstore extension into the current database, placing its
       objects in schema addons:

	   CREATE EXTENSION hstore SCHEMA addons;

       Another way to accomplish the same thing:

	   SET search_path = addons;

       Update a	pre-9.1	installation of	hstore into extension style:

	   CREATE EXTENSION hstore SCHEMA public FROM unpackaged;

       Be careful to specify the schema	in which you installed the existing
       hstore objects.

       CREATE EXTENSION	is a PostgreSQL	extension.


PostgreSQL 9.6.24		     2021		   CREATE EXTENSION(7)


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