Re: IN() Optimization issue in 8.0rc5

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Subject: Re: IN() Optimization issue in 8.0rc5
Date: 2005-01-15 21:32:27
Message-ID: 200501151332.27896.josh@agliodbs.com
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Tom,

> Hmm. What you want for a NOT IN is for it to say
> Filter: (NOT (hashed subplan))
> which you are not getting. What's the datatypes of the two personid
> columns?

INT

> Is the 400k-row estimate for person_attributes reasonable?

Yes, the estimates are completely accurate.

> Maybe you need to increase work_mem (nee sort_mem) to allow a
> 400k-row hash table?

Aha, that's it. I thought I'd already set that, but apparently it was a
different session. Fixed. Thanks!

--
Josh Berkus
Aglio Database Solutions
San Francisco

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