Re: 27 second plan times - Mailing list pgsql-hackers

From Tom Lane
Subject Re: 27 second plan times
Date
Msg-id 19950.1177136457@sss.pgh.pa.us
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In response to 27 second plan times  (Gregory Stark <stark@enterprisedb.com>)
Responses Re: 27 second plan times  (Gregory Stark <stark@enterprisedb.com>)
List pgsql-hackers
Gregory Stark <stark@enterprisedb.com> writes:
> I think there's still a problem here with some kind of n^2 behaviour for
> appends of very wide tables but I haven't quite nailed it yet. In any case is
> there any reason not to make the following small change to move the constraint
> exclusion ahead of the size estimates and index checks and save ourselves
> potentially a lot of work?

Applied along with some other hacking to reduce the costs of the
lower-level functions that this example shows to be inefficient.
They'd still be slow in large queries, whether CE applies or not.
        regards, tom lane


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