Nowak Micha*<michal.nowak@xxxxxx> wrote: > Lowering random_page_cost didn't help -- I've tried values 2.0 and > 1.5. First off, I don't remember you saying how much RAM is on the system, but be sure to set effective_cache_size to the sum of your shared_buffers and OS cache. I've often found that the optimizer undervalues cpu_tuple_cost; try setting that to 0.05. Then, depending on how well cached the active portion of your database is, you may want to drop your random_page_cost down close to or equal to seq_page_cost. If your cache hit rate is high enough, you might want to drop *both* seq_page_cost and random_page_cost to something as low as 0.1 or even 0.05. The objective is to model the actual costs of your workload against your data on your hardware. Sometimes that takes a bit of tinkering. -Kevin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
