Re: Query optimizer 8.0.1 (and 8.0)

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От Jim C. Nasby
Тема Re: Query optimizer 8.0.1 (and 8.0)
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Msg-id 20050216020000.GQ52357@decibel.org
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Ответ на Re: Query optimizer 8.0.1 (and 8.0)  (Ron Mayer <rm_pg@cheapcomplexdevices.com>)
Ответы Re: Query optimizer 8.0.1 (and 8.0)  (Bruce Momjian <pgman@candle.pha.pa.us>)
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On Mon, Feb 14, 2005 at 09:55:38AM -0800, Ron Mayer wrote:
> I still suspect that the correct way to do it would not be
> to use the single "correlation", but 2 stats - one for estimating
> how sequential/random accesses would be; and one for estimating
> the number of pages that would be hit.  I think the existing
> correlation does well for the first estimate; but for many data
> sets, poorly for the second type.
Should this be made a TODO? Is there some way we can estimate how much
this would help without actually building it?
-- 
Jim C. Nasby, Database Consultant               decibel@decibel.org 
Give your computer some brain candy! www.distributed.net Team #1828

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