postgresql7.1 select count(*) from (select r.object_id_two from acs_rels r, membership_rels mr where r.object_id_one = (select acs__magic_object_id('registered_users') from dual) and r.rel_id = mr.rel_id and mr.member_state not in ('banned','deleted','rejected') and r.object_id_two not in ( select r2.object_id_two from acs_rels r2, dotlrn_user_types dut where r2.object_id_one = dut.group_id)) as foo select distinct r.object_id_two from acs_rels r, membership_rels mr where r.object_id_one = (select acs__magic_object_id('registered_users') from dual) and r.rel_id = mr.rel_id and mr.member_state not in ('banned','deleted','rejected') and r.object_id_two not in ( select r2.object_id_two from acs_rels r2, dotlrn_user_types dut where r2.object_id_one = dut.group_id)