Re: Scrollable cursors and Sort performance

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>
Cc: Simon Riggs <simon(at)2ndquadrant(dot)com>, Martijn van Oosterhout <kleptog(at)svana(dot)org>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Scrollable cursors and Sort performance
Date: 2006-02-11 17:46:43
Message-ID: 200602111746.k1BHkhs02642@candle.pha.pa.us
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Jim C. Nasby wrote:
> 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?

Patch please.

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