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

From Tom Lane
Subject Re: [HACKERS] choose_bitmap_and again (was Re: Strangely Variable Query Performance)
Date
Msg-id 4535.1176565965@sss.pgh.pa.us
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In response to Re: Strangely Variable Query Performance  (Steve <cheetah@tanabi.org>)
List pgsql-performance
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"Dann Corbit" <DCorbit@connx.com> writes:
> Instead of sorting, I suggest the quickselect() algorithm, which is
> O(n).

What for?  Common cases have less than half a dozen entries.  That is
not the place we need to be spending engineering effort --- what we
need to worry about is what's the choice algorithm, not implementation
details.

            regards, tom lane

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