Re: Scrollable cursors and Sort performance

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От Jim C. Nasby
Тема Re: Scrollable cursors and Sort performance
Дата
Msg-id 20060227225531.GP82012@pervasive.com
обсуждение исходный текст
Ответ на Re: Scrollable cursors and Sort performance  (Simon Riggs <simon@2ndquadrant.com>)
Ответы Re: Scrollable cursors and Sort performance  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-hackers
On Mon, Feb 27, 2006 at 02:17:23PM +0000, Simon Riggs wrote:
> > Interesting point: how should EXPLAIN ANALYZE set these bits?  For its
> > own purposes it need not request random access, but it might be
> > interesting to make it possible to examine both the random and nonrandom
> > behaviors, now that these will be significantly different performancewise.
> > Possibly we could make EXPLAIN ANALYZE EXECUTE set the random-access
> > bits.
> 
> Good point. Whichever we do will be wrong in some cases.... I've no real
> opinion on this other than a vague preference for it to be quick.

Wouldn't an EXPLAIN ANALYZE DECLARE ... have the right information to
know if backward scan, etc was needed?
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461


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