The view pg_group exists for backwards compatibility: it emulates a catalog that existed in PostgreSQL before version 8.1. It shows the names and members of all roles that are marked as not rolcanlogin , which is an approximation to the set of roles that are being used as groups.

Table 49-62. pg_group Columns

Name Type References Description
groname name pg_authid .rolname Name of the group
grosysid oid pg_authid .oid ID of this group
grolist oid[] pg_authid .oid An array containing the IDs of the roles in this group