Re: "NOT IN" substantially slower in 9.0.2 than 8.3.13 - NOT EXISTS runs fast in both 8.3.13 and 9.0.2

From: Mladen Gogala <mladen(dot)gogala(at)vmsinfo(dot)com>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Achilleas Mantzios <achill(at)matrix(dot)gatewaynet(dot)com>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: "NOT IN" substantially slower in 9.0.2 than 8.3.13 - NOT EXISTS runs fast in both 8.3.13 and 9.0.2
Date: 2011-01-21 17:42:37
Message-ID: 4D39C58D.4060709@vmsinfo.com
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On 1/21/2011 12:09 PM, Robert Haas wrote:
> Looks like the bad selectivity estimate there is what's killing it.
> Not sure I completely understand why 9.0.2 is coming up with such a
> bad estimate, though.
>

I would recommend setting default_statistics_target to 1024 and
effective cache size to 20480MB and see what happens.

--

Mladen Gogala
Sr. Oracle DBA
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