Re: Scrollable cursors and Sort performance

From: Simon Riggs <simon(at)2ndquadrant(dot)com>
To: "Jim C(dot) Nasby" <jnasby(at)pervasive(dot)com>
Cc: 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 19:47:32
Message-ID: 1139687252.1258.607.camel@localhost.localdomain
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On Sat, 2006-02-11 at 11:44 -0600, 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?
>
> [1] http://www.postgresql.org/docs/8.1/interactive/sql-declare.html

Why do that ahead of me making the suggested changes?

Best Regards, Simon Riggs

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