Re: Problem with query plan - Mailing list pgsql-general

From Cott Lang
Subject Re: Problem with query plan
Date
Msg-id 1098488337.3551.80.camel@localhost
Whole thread Raw
In response to Re: Problem with query plan  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Problem with query plan
List pgsql-general
On Fri, 2004-10-22 at 14:19, Tom Lane wrote:
> Cott Lang <cott@internetstaff.com> writes:
> > sort_mem = 8192
> > random_page_cost = 2
> > effective_cache_size = 3932160
>
> effective_cache_size 30Gb ?  Seems a tad high ;-)

It's a 32GB machine with nothing else running on it except PG, buffers
hover around 31GB :)

> However, I set up a dummy test case on 7.4.5 and don't see any overflow.
> Can you try this exact test case and see if you get a NAN?

I don't. After a bounce, I also can't repeat my original case; it now
returns 16.60.

Fiddling with the above values, only setting sort_mem absurdly large
easily causes NAN.

My guess is there was a wonky setting for sort_mem that disappeared
after I bounced.


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