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Re: Shouldn't the planner have a higher cost for reverse index scans?

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: postgres performance list <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Shouldn't the planner have a higher cost for reverse index scans?
Date: 2009-04-10 17:46:43
Message-ID: 49DF8603.3000006@agliodbs.com (view raw or flat)
Thread:
Lists: pgsql-performance
Tom,

> Right, because they do.  If you think otherwise, demonstrate it.
> (bonnie tests approximating a reverse seqscan are not relevant
> to the performance of indexscans.)

Working on it.  I *think* I've seen this issue in the field, which is 
why I brought it up in the first place, but getting a good test case is, 
of course, difficult.


-- 
Josh Berkus
PostgreSQL Experts Inc.
www.pgexperts.com

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