Re: Query planner is using wrong index.

From: Brian Herlihy <btherl(at)yahoo(dot)com(dot)au>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: Query planner is using wrong index.
Date: 2006-04-07 00:15:38
Message-ID: 20060407001538.89517.qmail@web52308.mail.yahoo.com
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--- Dave Dutcher <dave(at)tridecap(dot)com> wrote:
> > -----Original Message-----
> > To: pgsql-performance(at)postgresql(dot)org
> > Subject: Re: [PERFORM] Query planner is using wrong index.
> [Snip]
> > I am really surprised that I have to go through such contortions just
> to
> > use
> > the primary key! This area of Postgres needs improvement.
> >
>
>
> Of course you mentioned that you are using 7.4.7. You might want to try
> upgrading to 8.1.3. There have been a lot of improvements to the
> performance since 7.4. I don't know if your specific problem was fixed,
> but it's worth a try.
>
> Also you might want to at least upgrade to 7.4.12 for the bug fixes.

Thanks for the suggestions. I've verified the same problem in 8.1.3 as well,
after my initial post. It was actually in 8.1.3 that I first discovered the
problem.

I noticed this item in the TODO list:

- Allow accurate statistics to be collected on indexes with more than one
column or expression indexes, perhaps using per-index statistics

This is what I need! But until that is added, I need a way to use the primary
key with the current version :)

Thanks,
Brian

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