Ubuntu Manpage: CREATE_EXTENSION - install an extension

Provided by: postgres-xc-client_1.1-2ubuntu2_amd64

NAME

       CREATE_EXTENSION - install an extension

SYNOPSIS

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

DESCRIPTION

       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.

PARAMETERS

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.

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

schema_name
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.

version
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.

old_version
FROMold_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 objects.

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 style.

NOTES

       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 views.

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

EXAMPLES

       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 hstore objects.

COMPATIBILITY

       CREATE EXTENSION is a PostgreSQL extension.