Re: MAX() and multi-column index on a partitioned table?

From: Dave Johansen <davejohansen(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-performance <pgsql-performance(at)postgresql(dot)org>
Subject: Re: MAX() and multi-column index on a partitioned table?
Date: 2015-05-22 23:53:19
Message-ID: CAAcYxUeoVw3CPFkvoCA7cETzNb-rBRpBeb4n3Dw3U6az6Zj-0g@mail.gmail.com
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On Fri, May 22, 2015 at 3:42 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Dave Johansen <davejohansen(at)gmail(dot)com> writes:
> > I'm trying to call MAX() on the first value of a multi-column index of a
> > partitioned table and the planner is choosing to do a sequential scan
> > instead of an index scan. Is there something I can do to fix this?
>
> What PG version are you using? 9.1 or newer should know how to do this
> with a merge append of several indexscans.
>

Sorry, I should have mentioned that in the original email. I'm using 8.4.20
on RHEL 6. From your reply, it sounds like this is the expected behavior
for 8.4 and 9.0. Is that the case?
Thanks,
Dave

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