On Tue, Dec 4, 2012 at 12:06 PM, <postgresql@xxxxxxxxx> wrote: > Slow version with bitmapscan enabled: http://explain.depesz.com/s/6I7 > Fast version with bitmapscan disabled: http://explain.depesz.com/s/4MWG If you check the "fast" plan, it has a higher cost compared against the "slow" plan. The difference between cost estimation and actual cost of your queries, under relatively precise row estimates, seems to suggest your e_c_s or r_p_c aren't a reflection of your hardware's performance. First, make sure caching isn't interfering with your results. Run each query several times. Then, if the difference persists, you may have to tweak effective_cache_size first, maybe random_page_cost too, to better match your I/O subsystem's actual performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
