From: Tom Lane <tgl@sss.pgh.pa.us>
To: Jason Turner <lefticus@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Changing location of ORDER BY has large effect on performance, but not results...
Date: Fri, 04 Nov 2005 09:47:58 -0500
Message-ID: <13380.1131115678@sss.pgh.pa.us> (raw)
In-Reply-To: <58e14cf00510281430y172deecak32839c101608522d@mail.gmail.com>
References: <58e14cf00510281430y172deecak32839c101608522d@mail.gmail.com>
Jason Turner <lefticus@gmail.com> writes:
> My initial guess is that it is not able to utilize the index on
> foo.tracktitle to sort the result set after foo has been joined with
> other tables.
Well, of course not. It should be able to do it before, though, and I'm
a bit surprised that you didn't get the same plan from both cases seeing
that the planner knows the first one is cheaper. Can you provide a
complete self-contained test case? I'm not interested in trying to
reverse-engineer your table definitions ...
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, lefticus@gmail.com
Subject: Re: Changing location of ORDER BY has large effect on performance, but not results...
In-Reply-To: <13380.1131115678@sss.pgh.pa.us>
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