The catalog pg_auth_members shows the membership relations between roles. Any non-circular set of relationships is allowed.

The view pg_tables provides access to useful information about each table in the database.

The catalog pg_shseclabel stores security labels on shared database objects. Security labels can be manipulated with the

The view pg_seclabels provides information about security labels. It as an easier-to-query version of the

The catalog pg_description stores optional descriptions (comments) for each database object. Descriptions can be manipulated with the

The catalog pg_foreign_table contains auxiliary information about foreign tables. A foreign table is primarily represented by a

The catalog pg_namespace stores namespaces. A namespace is the structure underlying SQL schemas: each namespace can have a separate collection

The catalog pg_collation describes the available collations, which are essentially mappings from an SQL name to operating system locale categories

Table 50-1 lists the system catalogs. More detailed documentation of each catalog follows below. Most system catalogs are copied from the template

The catalog pg_transform stores information about transforms, which are a mechanism to adapt data types to procedural languages. See