On Fri, Jul 15, 2005 at 20:08:32 +0300, Andrus <eetasoft@xxxxxxxxx> wrote: > > So I'll think still continuing to use null as unrestricted department > access. > > Is it reasonable to create unique constraint using > > CREATE UNIQUE INDEX user_id_permission_id_department_id_unique_idx > ON permission (user_id, permission_id, COALESCE(department_id,'ALL')) If you are going to do this a partial index is a better way to go. Something like: CREATE UNIQUE INDEX user_id_permission_id_null ON permission WHERE department_id IS NULL; However either of these let you insert and entry for "ALL" while also having entries for individual departments. ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings