The view pg_settings provides access to run-time parameters of the server. It is essentially an alternative interface to the

The catalog pg_aggregate stores information about aggregate functions. An aggregate function is a function that operates on a set of values

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

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

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

The catalog pg_largeobject holds the data making up "large objects". A large object is identified by an OID assigned

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

The pg_prepared_statements view displays all the prepared statements that are available in the current session. See

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

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