From: Tom Lane <tgl@sss.pgh.pa.us>
To: Joshua D. Drake <jd@commandprompt.com>
Cc: Sriram Dandapani <sdandapani@counterpane.com>
Cc: Pgsql-Performance (E-mail) <pgsql-performance@postgresql.org>
Subject: Re: select max(column) from parent table very slow
Date: Fri, 25 Aug 2006 00:33:27 -0400
Message-ID: <18394.1156480407@sss.pgh.pa.us> (raw)
In-Reply-To: <44EE4DA1.5060701@commandprompt.com>
References: <6992E470F12A444BB787B5C937B9D4DF057500BF@ca-mail1.cis.local>
<44EE4DA1.5060701@commandprompt.com>
"Joshua D. Drake" <jd@commandprompt.com> writes:
> Sriram Dandapani wrote:
>> Parent table has a column say column1 which is indexed (parent table and
>> all child tables are indexed on that column)
> In older versions of postgresql that would scan the whole table. In 8.1
> and above it doesn't. However, I am guess that since this is a
> partitioned table the planner isn't smart enough to just perform the
> query on each child and a max on the set that is returned.
It is not. Feel free to submit a patch for planagg.c ...
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, jd@commandprompt.com, sdandapani@counterpane.com
Subject: Re: select max(column) from parent table very slow
In-Reply-To: <18394.1156480407@sss.pgh.pa.us>
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