Re: View performance - Mailing list pgsql-performance

From Tom Lane
Subject Re: View performance
Date
Msg-id 2713.1040932214@sss.pgh.pa.us
Whole thread Raw
In response to Re: View performance  (Bruno Wolff III <bruno@wolff.to>)
List pgsql-performance
Bruno Wolff III <bruno@wolff.to> writes:
> By disabling merge joins and using the updated view, I got the query down
> to about 25% of its original runtime.
> Note the query estimate is off by a factor of more than 10.

This seems to indicate some estimation problems in cost_hashjoin; the
estimated cost for the hashjoin is evidently a lot higher than it should
be.

Are you interested in digging into this; or could you send me a dump of
the tables used in the view and query, so I could look into it?

            regards, tom lane

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