Re: [HACKERS] choose_bitmap_and again (was Re: [PERFORM] Strangely Variable Query Performance) - Mailing list pgsql-patches

From Tom Lane
Subject Re: [HACKERS] choose_bitmap_and again (was Re: [PERFORM] Strangely Variable Query Performance)
Date
Msg-id 26103.1176613862@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] choose_bitmap_and again (was Re: [PERFORM] Strangely Variable Query Performance)  (Steve <cheetah@tanabi.org>)
Responses Re: [HACKERS] choose_bitmap_and again (was Re: [PERFORM] Strangely Variable Query Performance)  (Steve <cheetah@tanabi.org>)
Re: [HACKERS] choose_bitmap_and again (was Re: [PERFORM] Strangely Variable Query Performance)  (Steve <cheetah@tanabi.org>)
List pgsql-patches
Steve <cheetah@tanabi.org> writes:
>> Steve, can you try this out on your queries and see if it makes better
>> or worse decisions?  It seems to fix your initial complaint but I do
>> not have a large stock of test cases to try.

>      Wow, this is a remarkable difference.  Queries that were taking
> minutes to complete are coming up in seconds.  Good work, I think this'll
> solve my customer's needs for their demo on the 19th :)

Can you find any cases where it makes a worse choice than before?
Another thing to pay attention to is whether the planning time gets
noticeably worse.  If we can't find any cases where it loses badly
on those measures, I'll feel comfortable in applying it...

            regards, tom lane

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