## 51.22. `pg_extension`

The catalog `pg_extension` stores information about the installed extensions. See Section 37.16 for details about extensions.

Table 51.22. `pg_extension` Columns

Name | Type | References | Description
--- | --- | --- | ---
`oid` | `oid` |  | Row identifier (hidden attribute; must be explicitly selected)
`extname` | `name` |  | Name of the extension
`extowner` | `oid` | ``pg_authid`.oid` | Owner of the extension
`extnamespace` | `oid` | ``pg_namespace`.oid` | Schema containing the extension's exported objects
`extrelocatable` | `bool` |  | True if 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's configuration table(s), or `NULL` if none
`extcondition` | `text[]` |  | Array of `WHERE`-clause filter conditions for the extension's configuration table(s), or `NULL` if none

Note that unlike most catalogs with a “namespace” column, `extnamespace` is not meant to imply that the extension belongs to that schema. Extension names are never schema-qualified. Rather, `extnamespace` indicates the schema that contains most or all of the extension's objects. If `extrelocatable` is true, then this schema must in fact contain all schema-qualifiable objects belonging to the extension.