You are right along with the others, the seq scan was only forced because of the varchar-text comparision.. Using the cast solves the problem. Thanks for the answers everyone! Balazs -----Original Message----- From: Fernando Hevia [mailto:fhevia@xxxxxxxxxxxxx] Sent: Tuesday, January 05, 2010 3:16 PM To: 'Keresztury Balázs'; pgsql-performance@xxxxxxxxxxxxxx Subject: RE: forced sequential scan when condition has current_user > -----Mensaje original----- > De: Keresztury Balázs > > hi, > > just a small question: is it normal that PostgreSQL 8.4.1 > always uses sequential scanning on any table when there is a > condition having the constant "current_user"? Of course there > is a btree index set on that table, but the DBMS just doesn't > want to utilize it. When I replace current_user to any > string, the planner uses the index normally. > > I can demonstrate it with the following simple query: > > SELECT psz.kotesszam FROM projekt.projektszervezet psz WHERE > psz.felhasznalo_id = current_user; > Probably you are comparing different types. Try explicitly casting current_user to text: SELECT psz.kotesszam FROM projekt.projektszervezet psz WHERE psz.felhasznalo_id = current_user::text -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
