Re: Weird 8.2.4 performance - Mailing list pgsql-performance

From Mark Kirkwood
Subject Re: Weird 8.2.4 performance
Date
Msg-id 46688F16.90207@paradise.net.nz
Whole thread Raw
In response to Re: Weird 8.2.4 performance  (Kurt Overberg <kurt@hotdogrecords.com>)
Responses Re: Weird 8.2.4 performance  ("Joshua D. Drake" <jd@commandprompt.com>)
List pgsql-performance
Kurt Overberg wrote:
> work_mem = 100MB                        # when I ran the original query,
> this was set to 1MB, increased on Mark Kirkwood's advice, seemed to help
> a bit but not really
>

For future reference, be careful with this parameter, as *every*
connection will use this much memory for each sort or hash (i.e it's not
shared and can be allocated several times by each connection!)...yeah, I
know I suggested increasing it to see what effect it would have :-).

And I'd agree with Steiner and others, looks like caching effects are
the cause of the timing difference between production and the mac!

Cheers

Mark




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