On 8 October 2011 19:47, Pavel Stehule <pavel.stehule@xxxxxxxxx> wrote: >>> I did it. It is strange, so your times are significantly slower than I >>> have. Have you enabled asserts? >> >> The table contains 15 million rows with column values randomly >> selected from the 1-350 range, with 60% within the 1-50 range, and >> asserts are enabled. >> > > Now I repeated tests on litlle bit wide table with 9 milion rows, but > without success. > > Try to disable asserts. I am not sure, but maybe there significantlly > change a speed. Okay, here you go. Results with debug_assertions = false: Index-only scan: 173.389 ms (78.442 ms) Index scan: 184239.399 ms (previously 164882.666 ms) Bitmap scan: 159354.261 ms (previously 154107.415 ms) Sequential scan: 134552.263 ms (previously 121296.999 ms) So no particularly significant difference, except with the index-only scan (which I repeated 3 times and it's about the same each time). -- Thom Brown Twitter: @darkixion IRC (freenode): dark_ixion Registered Linux user: #516935 EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
