On tor, 2012-01-05 at 10:04 +0000, Benedikt Grundmann wrote: > We have recently upgrade two of our biggest postgres databases > to new hardware and minor version number bump (8.4.5 -> 8.4.9). > > We are experiencing a big performance regression in some queries. > In those cases the planner seems to choose a nested loop index > scan instead of hashing the index once and then joining.
There was a planner regression introduced in version 8.4.8, which was thought to be fixed in 8.4.9. Maybe you got caught by that. See Message-Id: <760c0206-b5f4-4dc6-9296-b7a730b7f...@silentmedia.com> for some information. Check if your queries match that pattern. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
