Re: hashjoin chosen over 1000x faster plan - Mailing list pgsql-performance

From Simon Riggs
Subject Re: hashjoin chosen over 1000x faster plan
Date
Msg-id 1191997904.4233.125.camel@ebony.site
Whole thread Raw
In response to hashjoin chosen over 1000x faster plan  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: hashjoin chosen over 1000x faster plan  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-performance
On Tue, 2007-10-09 at 15:09 -0500, Kevin Grittner wrote:

> I have a situation where a query is running much slower than I would
> expect.  The ANALYZE showed that it is hashing some information which
> is rarely needed.  When I set enable_hashjoin = off for the
> connection the query run in 1/1000 the time.

Can you confirm the two queries give identical outputs? It isn't clear
to me why the second sort is (never executed) in your second plan, which
I would only expect to see for an inner merge join.

Can you show the details for ControlRecord also.

--
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com


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