Tom Lane wrote: > 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. understood - I was not trying to imply that we suffer a 30% performance drop overall. But still it means we know about a set of queries that we once could handle faster than we can now ... Stefan
