On Wed, Aug 11, 2010 at 11:41 PM, Greg Smith <greg@xxxxxxxxxxxxxxx> wrote: > Sandeep Srinivasa wrote: >> >> Maybe a tabular form would be nice - "work_mem" under... > > The problem with work_mem in particular is that the useful range depends > quite a bit on how complicated you expect the average query running to be. And it's very dependent on max connections. A machine with 512GB that runs batch processes for one or two import processes and then has another two or three used to query it can run much higher work_mem than a machine with 32G set to handle hundreds of concurrent accesses. Don't forget that when you set work_mem to high it has a very sharp dropoff in performance as swapping starts to occur. If work_mem is a little low, queries run 2 or 3 times slower. If it's too high the machine can grind to a halt. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general