André Volpato <andre.volpato@xxxxxxxxxxxxxxxxxxxxx> writes: > Gregory Stark escreveu: >> André Volpato <andre.volpato@xxxxxxxxxxxxxxxxxxxxx> writes: >> >> I think the answer is that if you have bad statistics you'll get a bad plan >> and which bad plan is going to be pretty much random. >> > I believe the statistics are ok, I´ve runned vacuum analyze before all those > tries. Sorry, I should have said "bad estimates". That is, because of the j*1.5 BETWEEN 3000000 AND 4000000 clause the optimizer isn't going to be able to come up with a good estimate of how many rows that will match. What plan it picks when it has such a bad estimate is going to be pretty random, dependant on just what plans would be good in a situation entirely unrelated to the reality. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's Slony Replication support! ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org/
