Re: [GENERAL] Very slow queries w/ NOT IN preparation (seems like a bug, test case)

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Sergey Konoplev" <gray(dot)ru(at)gmail(dot)com>, "Richard Huxton" <dev(at)archonet(dot)com>, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [GENERAL] Very slow queries w/ NOT IN preparation (seems like a bug, test case)
Date: 2008-11-13 00:24:01
Message-ID: 23148.1226535841@sss.pgh.pa.us
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I wrote:
>> 2. Put some arbitrary limit on the number of subconditions in an AND or
>> OR clause before we give up and don't attempt to prove anything about
>> it.

> So option #2 with a cutoff of 100 items or so is looking like the
> best response.

I've applied a patch along this line to 8.2 and up, and also installed
some code (in HEAD only) to cache the results of proof-operator lookup.

regards, tom lane

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