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

The catalog pg_range stores information about range types. This is in addition to the types' entries in

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

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

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

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

The catalog pg_amop stores information about operators associated with access method operator families. There is one row for each operator that

The catalog pg_authid contains information about database authorization identifiers (roles). A role subsumes the concepts of

The pg_replication_origin catalog contains all replication origins created. For more on replication origins see Chapter 48.