On Tue, Jun 14, 2005 at 08:33:34 -0500, Peter Fein <pfein@xxxxxxxxx> wrote: > > Knowing the specifics of the data I'm putting in sometext, a halfway > decent hash function would make collisions so rare as to make the chance > insignificant (and collisions wouldn't break anything anyway). Is this > approach reasonable, or should I use a hash index on (group_id, > sometext) - does this suffer from the same size limitation as btrees? I > thought hash indexes were slow... The hash value should be saved as a separate column. Then it sounds like you want a partial btree index of (group_id, hash) where the flag is set. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq