From: Albert Cervera Areny <albert@sedifa.com>
To: pgsql-performance@postgresql.org
Subject: Re: Posible planner improvement?
Date: Wed, 21 May 2008 18:22:42 +0200
Message-ID: <200805211822.42528.albert@sedifa.com> (raw)
In-Reply-To: <48341F1D.3090304@archonet.com>
References: <014F2941B0A1EA47BD61D21526B806E90162C3D2@MI8NYCMAIL08.Mi8.com>
<48341F1D.3090304@archonet.com>
A Dimecres 21 Maig 2008, Richard Huxton va escriure:
> Luke Lonergan wrote:
> > The problem is that the implied join predicate is not being
> > propagated. This is definitely a planner deficiency.
>
> IIRC only equality conditions are propagated and gt, lt, between aren't.
> I seem to remember that the argument given was that the cost of
> checking for the ability to propagate was too high for the frequency
> when it ocurred.
>
> Of course, what was true for code and machines of 5 years ago might not
> be so today.
Hope this can be revisited given the huge difference in this case: 80 minutes
to 1 second.
--
Albert Cervera Areny
Dept. Informàtica Sedifa, S.L.
Av. Can Bordoll, 149
08202 - Sabadell (Barcelona)
Tel. 93 715 51 11
Fax. 93 715 51 12
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To: pgsql-performance@postgresql.org
Cc: albert@sedifa.com
Subject: Re: Posible planner improvement?
In-Reply-To: <200805211822.42528.albert@sedifa.com>
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