From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Tobias Brox <tobias@nordicbet.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: Merge Join vs Nested Loop
Date: Wed, 27 Sep 2006 10:19:24 -0500
Message-ID: <1159370365.4643.7.camel@localhost.localdomain> (raw)
In-Reply-To: <20060927150512.GE17834@oppetid.no>
References: <20060926193553.GA27268@oppetid.no>
<719.1159308596@sss.pgh.pa.us>
<20060927094803.GA11245@oppetid.no>
<1159369111.4643.0.camel@localhost.localdomain>
<20060927150512.GE17834@oppetid.no>
On Wed, 2006-09-27 at 17:05 +0200, Tobias Brox wrote:
> [Scott Marlowe - Wed at 09:58:30AM -0500]
> > Have you tried chaning the cpu_* cost options to see how they affect
> > merge versus nested loop?
>
> As said in the original post, increasing any of them shifts the planner
> towards nested loops instead of merge_join. I didn't check which one of
> the cost constants made the most impact.
So, by decreasing them, you should move away from nested loops then,
right? Has that not worked for some reason?
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To: pgsql-performance@postgresql.org
Cc: smarlowe@g2switchworks.com, tobias@nordicbet.com, tgl@sss.pgh.pa.us
Subject: Re: Merge Join vs Nested Loop
In-Reply-To: <1159370365.4643.7.camel@localhost.localdomain>
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