System Catalogs Definitions - pg_extension - 《Greenplum Database v6.23 Documentation》

The system catalog table pg_extension stores information about installed extensions.

column	type	references	description
`extname`	name		Name of the extension.
`extowner`	oid	pg_authid.oid	Owner of the extension
`extnamespace`	oid	pg_namespace.oid	Schema containing the extension exported objects.
`extrelocatable`	boolean		True if the extension can be relocated to another schema.
`extversion`	text		Version name for the extension.
`extconfig`	oid[]	pg_class.oid	Array of `regclass` OIDs for the extension configuration tables, or `NULL` if none.
`extcondition`	text[]		Array of `WHERE`-clause filter conditions for the extension configuration tables, or `NULL` if none.

Unlike most catalogs with a namespace column, extnamespace does not imply that the extension belongs to that schema. Extension names are never schema-qualified. The extnamespace schema indicates the schema that contains most or all of the extension objects. If extrelocatable is true, then this schema must contain all schema-qualifiable objects that belong to the extension.

Parent topic: System Catalogs Definitions