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Re: Query that uses lots of memory in PostgreSQL 9.2.1 in Windows 7 - Mailing list pgsql-performance

From Merlin Moncure
Subject Re: Query that uses lots of memory in PostgreSQL 9.2.1 in Windows 7
Date
Msg-id CAHyXU0yvvBmANx5ohmsGWK5iXT_cpLYf9-ey-iMsatsWJNYPdQ@mail.gmail.com
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In response to Re: Query that uses lots of memory in PostgreSQL 9.2.1 in Windows 7  (Pavel Stehule <pavel.stehule@gmail.com>)
List pgsql-performance
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On Tue, Nov 20, 2012 at 1:27 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> Hello
>
> HashSetOp is memory expensive operation, and should be problematic
> when statistic estimation is bad.
>
> Try to rewritre this query to JOIN

or, 'WHERE NOT EXISTS'.   if 41 seconds seems like it's too long, go
ahead and post that plan and maybe that can be optimized.

merlin

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