> The WHERE condition can be divided into a "slowly changing" part and in > a "random" one. The random part is the one I change at every query to avoid > result caching. The first query will leave in cache at least many of the index pages needed by the second query, and likely actual rows needed by the second query. > Disk cache could explain the thing, but then why I got the high performances > after the partial index has been created? By chance? Creating the partial index reads rows, and the pages are left in the disk cache. The only way to do proper comparisons is to reboot between trials in order to compare queries with cold caches, or use the latter of multiple runs in order to compare queries with hot caches. -- Scott Ribe scott_ribe@xxxxxxxxxxxxxxx http://www.killerbytes.com/ (303) 722-0567 voice -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
