On Mon, 2004-07-26 at 08:20, Gaetano Mendola wrote: > Hervà Piedvache wrote:
SNIP > > sort_mem = 512000 > > This is too much, you are instructing Postgres to use 512MB > for each backend ( some time each backend can use this quantity > more then one ) agreed. If any one process needs this much sort mem, you can set it in that sessions with set sort_mem anyway, so to let every sort consume up to 512 meg is asking for trouble. > > effective_cache_size = 5000000 > > 5GB for 8 GB system is too much No, it's not. Assuming that postgresql with all it's shared buffers is using <2 gig, it's quite likely that the kernel is caching at least 5 gigs of disk data. Effective cache size doesn't set any cache size, it tells the planner about how much the kernel is caching. > > random_page_cost = 3 > > on your HW you can decrease it to 2 > and also decrease the other cpu costs On fast machines it often winds up needing to be set somewhere around 1.2 to 2.0 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html