On Wed, 5 May 2004, Chris Gamache wrote: > When I run an query (that I have identified as expensive, and non-critical), I > would like to be able to take its priority down a few notches to allow the > standard every-day tasks of the DB to run unhindered. As it stands, postmasters > elbow each other out for processor time, and it seems like one expensive query > can bring other DB functions to a crawl. > > Hardware : Dual P4 Xeon 2.8GHz; 1 GB RAM; ULTRA320 RAID 10 with an ext3 > filesystem > PostgreSQL 7.4.2 > > What can be done to allow for smarter preemption? Could I do anything at the OS > level to throttle that particular postmaster's process? I'm running (IMO) a > balanced config, but there's always room for improvement. Its that oddball > query that comes around once every so often that causes the problem.
It is inadvisable to change priority of backends as that could lead to deadlocks in certain situations I believe. Have you read: http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html yet? It may just be that you don't have enough shared_buffers or whatnot. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
