> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cockroachlabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# System Catalogs

CockroachDB includes a set of system catalogs that provide non-stored data to client applications.

The following system catalogs are available as schemas preloaded to every database:

* [`information_schema`](/docs/stable/information-schema), a schema provided for compatibility with the SQL standard.
* [`crdb_internal`](/docs/stable/crdb-internal), a schema with information about CockroachDB internals.
* [`pg_catalog`](/docs/stable/pg-catalog),  a schema provided for compatibility with PostgreSQL.
* [`pg_extension`](/docs/stable/pg-extension), a schema catalog with information about CockroachDB extensions.

Access to the `crdb_internal` schema and to tables and built-in functions in the `system` database is controlled by the [`allow_unsafe_internals` session variable](/docs/stable/session-variables#allow-unsafe-internals), which defaults to `off`. Queries to these namespaces will fail unless access is manually enabled. Usage is also audited via the [`SENSITIVE_ACCESS` logging channel](/docs/stable/logging-use-cases#example-unsafe-internals). For more information, see [`crdb_internal` access control](/docs/stable/crdb-internal#access-control). The `system` and `crdb_internal` schemas are intended for advanced support scenarios only, and should be accessed under the guidance of Cockroach Labs.

> [!CAUTION]
>
> Tables in the system catalogs have varying levels of stability. Not all system catalog tables are meant for programmatic purposes. For more information, see [API Support Policy](/docs/stable/api-support-policy.md).

To see all of the system catalogs for the [current database](/docs/stable/sql-name-resolution.md#current-database), you can use a [`SHOW SCHEMAS`](/docs/stable/show-schemas) statement:

```sql theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
> SHOW SCHEMAS;
```

```
     schema_name     | owner
---------------------+--------
  crdb_internal      | NULL
  information_schema | NULL
  pg_catalog         | NULL
  pg_extension       | NULL
  public             | admin
(5 rows)
```

## See also

* [`SHOW`](/docs/stable/show-vars)
* [`SHOW SCHEMAS`](/docs/stable/show-schemas)
* [SQL Name Resolution](/docs/stable/sql-name-resolution.md)