Stefan Kaltenbrunner <stefan@xxxxxxxxxxxxxxxx> writes: > Arjen van der Meijden wrote: >> Stefan Kaltenbrunner wrote: >>> ouch - do I read that right that even after tom's fixes for the >>> "regressions" in 8.2.0 we are still 30% slower then the -HEAD checkout >>> from the middle of the 8.2 development cycle ? >> >> Yes, and although I tested about 17 different cvs-checkouts, Tom and I >> weren't really able to figure out where "it" happened. So its a bit of a >> mystery why the performance is so much worse. > double ouch - losing that much in performance without an idea WHY it > happened is really unfortunate :-( Keep in mind that Arjen's test exercises some rather narrow scenarios; IIRC its performance is mostly determined by some complicated bitmap-indexscan cases. So that "30% slower" bit certainly doesn't represent an across-the-board figure. As best I can tell, the decisions the planner happened to be making in late June were peculiarly nicely suited to his test, but not so much for other cases. regards, tom lane
