Provided by: postgresql-client-9.1_9.1.3-2_i386
CREATE_EXTENSION - install an extension
CREATE EXTENSION [ IF NOT EXISTS ] extension_name
[ WITH ] [ SCHEMA schema ]
[ VERSION version ]
[ FROM old_version ]
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.
IF NOT EXISTS
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.
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
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
For information about writing new extensions, see Section 35.15,
"Packaging Related Objects into an Extension", in the documentation.
Install the hstore extension into the current database:
CREATE EXTENSION hstore;
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
CREATE EXTENSION is a PostgreSQL extension.
ALTER EXTENSION (ALTER_EXTENSION(7)), DROP EXTENSION