Re: How to avoid hashjoin and mergejoin

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Carlo Stonebanks" <stonec(dot)register(at)sympatico(dot)ca>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: How to avoid hashjoin and mergejoin
Date: 2007-11-01 21:41:58
Message-ID: 15853.1193953318@sss.pgh.pa.us
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"Carlo Stonebanks" <stonec(dot)register(at)sympatico(dot)ca> writes:
> Still, the Linux server did not create the same, fast plan as the Windows
> server. In order to get the same plan we had to:

> set enable_hashjoin to 'off';
> set enable_mergejoin to 'off';

This is just about never the appropriate way to solve a performance
problem, as it will inevitably create performance problems in other
queries.

What I'm wondering is whether the tables have been ANALYZEd recently,
and also whether there are any nondefault postgresql.conf settings in
use on the other server.

regards, tom lane

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