From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: Gauri Kanekar <meetgaurikanekar@gmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Query Planner
Date: Mon, 26 Feb 2007 12:52:27 +0100
Message-ID: <20070226115227.GA4338@uio.no> (raw)
In-Reply-To: <7e4ba9550702260349r7c550aa2mb0b610874645b3c3@mail.gmail.com>
References: <7e4ba9550702260349r7c550aa2mb0b610874645b3c3@mail.gmail.com>
On Mon, Feb 26, 2007 at 05:19:05PM +0530, Gauri Kanekar wrote:
> I have a Query. So when i do explain analyse on it , it shows me many Hash
> Joins.
> So is it possible to indicate the Query Planner not to consider Hash Join.
set enable_hashjoin = false;
This is very often the wrong solution, though. If hash join is indeed slower
than merge join, the planner should have guessed so, and it would be better
to find out why the planner guessed wrong, and correct it somehow.
/* Steinar */
--
Homepage: http://www.sesse.net/
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To: pgsql-performance@postgresql.org
Cc: sgunderson@bigfoot.com, meetgaurikanekar@gmail.com
Subject: Re: Query Planner
In-Reply-To: <20070226115227.GA4338@uio.no>
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