From: Tom Lane <tgl@sss.pgh.pa.us>
To: Tobias Brox <tobias@nordicbet.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: max/min and index usage
Date: Tue, 05 Dec 2006 22:29:53 -0500
Message-ID: <17474.1165375793@sss.pgh.pa.us> (raw)
In-Reply-To: <20061206030156.GA29255@oppetid.no>
References: <20061206030156.GA29255@oppetid.no>
Tobias Brox <tobias@nordicbet.com> writes:
> We're using 8.1 - I thought such a construct was safe in pg 8.1:
> select max(indexed_value) from huge_table;
> while earlier we had to use:
> select indexed_value from huge_table order by indexed_value desc limit 1;
These are not actually exactly the same thing. In particular, I suppose
your table contains a lot of nulls?
regards, tom lane
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To: pgsql-performance@postgresql.org
Cc: tgl@sss.pgh.pa.us, tobias@nordicbet.com
Subject: Re: max/min and index usage
In-Reply-To: <17474.1165375793@sss.pgh.pa.us>
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