## 51.22. `pg_extension`

The catalog `pg_extension` stores information about the installed extensions. See Section 37.17 for details about extensions.

Table 51.22. `pg_extension` Columns

Column Type Description
`oid` `oid` Row identifier
`extname` `name` Name of the extension
`extowner` `oid` (references `pg_authid`.`oid`) Owner of the extension
`extnamespace` `oid` (references `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[]` (references `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.