Re: Scrollable cursors and Sort performance - Mailing list pgsql-hackers

From Jim C. Nasby
Subject Re: Scrollable cursors and Sort performance
Date
Msg-id 20060210162244.GQ57845@pervasive.com
Whole thread Raw
In response to Scrollable cursors and Sort performance  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: Scrollable cursors and Sort performance
List pgsql-hackers
On Fri, Feb 10, 2006 at 01:32:44PM +0000, Simon Riggs wrote:
> I intend to add a short patch to pass down the cursor state during
> planning, so that when it is explicitly specified the sort node is able
> to recognise this and avoid work. Also, to add a GUC to force the
> not-explicitly-specified case to be the same as the NO SCROLL case, as
> the standard requires.

So is this only an issue if you're using a cursor, or does this affect
plain SELECT ... ORDER BY as well?

Reason I'm asking is that users should be able to explicitly be able to
turn the extra step off somehow. I'm not clear if NO SCROLL is
sufficient to do that or not.
-- 
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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