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Re: svn commit: r1081484 - in /subversion/trunk/subversion/libsvn_wc: wc-queries.sql wc_db.c

From: Stefan Sperling <stsp_at_elego.de>
Date: Mon, 28 Mar 2011 14:31:59 +0200

On Mon, Mar 28, 2011 at 07:49:22AM -0400, Greg Stein wrote:
> On Mar 28, 2011 7:41 AM, "Greg Stein" <gstein_at_gmail.com> wrote:
> > Think about how the query optimizer/planner would work. Consider whether a
> result set needs to be constructed.
> >
> > ... a LIMIT 1 provides a ton of help to the SQL engine about what needs to
> be fetched (or not).
> >
> > There is also a semantic element to it. Readers of the code will see that
> you're looking for basic presence rather than a set of results.
> >
> > If/when you need a query containing the set of nodes with mods, then you
> can consider another query. Until that time, the LIMIT is helpful/best.
> >
> > Cheers,
> > -g
>
> In fact, you can switch from selecting local_relpath to a simple 1:
>
> --STMT_ANY_NODES_WITH_PROP_MODS
> SELECT 1 FROM ...
>
> (note stmt name change, too)

Fair enough. Does r1086208 look better?
Received on 2011-03-28 14:32:37 CEST

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