From: Marko Niinimaki <manzikki@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: slow subselects
Date: Wed, 21 Feb 2007 14:34:35 +0900
Message-ID: <58b7e6510702202134n45e1ef87tc8bc62b2586c43d7@mail.gmail.com> (raw)
In-Reply-To: <22952.1171957386@sss.pgh.pa.us>
References: <58b7e6510702192302i6b526e56wee847a2122cec3aa@mail.gmail.com>
<58b7e6510702192310v77517652q4ba8ecaf50ea161c@mail.gmail.com>
<22952.1171957386@sss.pgh.pa.us>
Many thanks! Ismo's reply solved the problem, and Tom's reply solved
another one.
Marko
Ismo Tuononen wrote:
> select studentid,max(score) from studentprofile group by studentid;
On 20/02/07, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> The optimal index for this would be on studentprofile(studentid,score).
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To: pgsql-performance@postgresql.org
Cc: manzikki@gmail.com, tgl@sss.pgh.pa.us
Subject: Re: slow subselects
In-Reply-To: <58b7e6510702202134n45e1ef87tc8bc62b2586c43d7@mail.gmail.com>
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