Re: Scrollable cursors and Sort performance

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От Jim C. Nasby
Тема Re: Scrollable cursors and Sort performance
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Msg-id 20060211174435.GL57845@pervasive.com
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Ответ на Re: Scrollable cursors and Sort performance  ("Jim C. Nasby" <jnasby@pervasive.com>)
Ответы Re: Scrollable cursors and Sort performance  (Bruce Momjian <pgman@candle.pha.pa.us>)
Re: Scrollable cursors and Sort performance  (Simon Riggs <simon@2ndquadrant.com>)
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On Sat, Feb 11, 2006 at 11:32:02AM -0600, Jim C. Nasby wrote:
> I think the point that Martijn was trying to make was that per our docs
> it would be perfectly acceptable for us to make any cursor NO SCROLL
> implicitly if it means less work for the optimizer.

Ok, I take that back. The actual quote[1] is:

"Depending upon the complexity of the query's execution plan, specifying
SCROLL may impose a performance penalty on the query's execution time."

Clearly that says it can affect execution time, not that we're free to
alter the default behavior at will.

But speaking of documentation, it doesn't actually say what the default
is. Care update that, or should I formally submit a patch?

[1] http://www.postgresql.org/docs/8.1/interactive/sql-declare.html
-- 
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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