## 52.22. `pg_extension`
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The catalog `pg_extension` stores information about the installed extensions. See [Section 38.17](extend-extensions.html) for details about extensions.
**Table 52.22. `pg_extension` Columns**
| Column Type
Description |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `oid` `oid`
Row identifier |
| `extname` `name`
Name of the extension |
| `extowner` `oid` (references [`pg_authid`](catalog-pg-authid.html).`oid`)
Owner of the extension |
| `extnamespace` `oid` (references [`pg_namespace`](catalog-pg-namespace.html).`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`](catalog-pg-class.html).`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.