Re: Postgres refusing to use >1 core - Mailing list pgsql-performance

From Shaun Thomas
Subject Re: Postgres refusing to use >1 core
Date
Msg-id 4DCC06A9.9020509@peak6.com
Whole thread Raw
In response to Re: Postgres refusing to use >1 core  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
On 05/12/2011 11:07 AM, Tom Lane wrote:

> I find it odd that replacing the subquery with a temp table helps,
> though, because (unless you stuck in an ANALYZE you didn't mention)
> it would have no stats at all about the number of groups in the temp
> table.

I did have an analyze initially for exactly that reason. But what I
found odd is that in my rush to execute this for the end of day reports,
I forgot that step, and it still ran fine. I've found that the planner
tends to treat un-analyzed tables somewhat pessimistically, which is
fine by me.

--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com

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