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Re: Query improvement - Mailing list pgsql-performance

From Robert Haas
Subject Re: Query improvement
Date
Msg-id BANLkTimV2Y8uT6SjsvZhR1kZ5Pf8+HPtYg@mail.gmail.com
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In response to Re: Query improvement  (Claudio Freire <klaussfreire@gmail.com>)
List pgsql-performance
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On Mon, May 2, 2011 at 3:58 AM, Claudio Freire <klaussfreire@gmail.com> wrote:
> Hash joins are very inefficient if they require big temporary files.

Hmm, that's not been my experience.  What have you seen?

I've seen a 64-batch hash join beat out a
nested-loop-with-inner-indexscan, which I never woulda believed,
but...

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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