Re: bad estimates - Mailing list pgsql-performance

From Tom Lane
Subject Re: bad estimates
Date
Msg-id 22271.1062254152@sss.pgh.pa.us
Whole thread Raw
In response to Re: bad estimates  (Ken Geis <kgeis@speakeasy.org>)
List pgsql-performance
Ken Geis <kgeis@speakeasy.org> writes:
>  From what I've learned, we want to convince the optimizer to use a
> table scan; that's a good thing.  I want it to use hashed aggregates,
> but I can't convince it to (unless maybe I removed all of the
> statistics.)

You probably just need to increase sort_mem.  Multiple aggregates take
more RAM to process in a hashtable style ...

            regards, tom lane

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