Re: Optimising "in" queries

From: Michael Glaesemann <grzm(at)seespotcode(dot)net>
To: Russell Smith <mr-russ(at)pws(dot)com(dot)au>
Cc: Stephen Davies <scldad(at)sdc(dot)com(dot)au>, pgsql-performance(at)postgresql(dot)org
Subject: Re: Optimising "in" queries
Date: 2007-08-22 13:25:26
Message-ID: AAF53AEE-B98C-45BD-B80F-8FA528BFB98B@seespotcode.net
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On Aug 22, 2007, at 5:58 , Russell Smith wrote:

> Stephen Davies wrote:
>> select count(rdate),rdate from reading where sensor_id in
>> (1137,1138,1139,1140) group by rdate order by rdate desc limit 1;
>>
>>
> It would have been helpful to see the table definition here. I can
> say up front that array processing in postgres is SLOW.

Um, what array processing are you seeing here? IN (a, b, b) is not an
array construct.

Michael Glaesemann
grzm seespotcode net

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