Tom Lane wrote: > rihad <[EMAIL PROTECTED]> writes: > > Given this table: > > CREATE TABLE foo ( > > id integer primary key, > > bar_id integer references bar (id) > > ); > > and provided that bar.id is itself a PK, do I still need to create an > > index on bar_id if often doing queries like: > > SELECT MIN(id) FROM foo WHERE bar_id IS NULL; > > Now as far as the above-illustrated query goes, no simple index is going > to help it, because IS NULL is not an indexable operation.
Unless you are on 8.3, that is. -- Alvaro Herrera http://www.amazon.com/gp/registry/CTMLCN8V17R4 Y dijo Dios: "Que sea Satanás, para que la gente no me culpe de todo a mí." "Y que hayan abogados, para que la gente no culpe de todo a Satanás" ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
