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Re: Errors and Optimization: re-ordering predicates

From: Adam Retter <adam@exist-db.org>
Date: Sun, 3 Jan 2016 19:52:50 +0000
Message-ID: <CAJKLP9YBpxyo_HzQrmOqOdQVLJY1WXe3X87bg1BKV3CMZbswXA@mail.gmail.com>
To: Michael Kay <mike@saxonica.com>
Cc: Public Joint XSLT XQuery XPath <public-xsl-query@w3.org>
> I am torn here. Are other products exploiting the freedom which we give to implementors in this area? Are users of those products complaining? Or are implementors showing restraint by finding a compromise between performance and usability?
>

eXist does not do much in the way of predicate reordering, currently
we suggest to users to put the most selective predicates first as we
evaluate them from left-to-right. In future, we could do more
intelligent reordering based on index statistics.



-- 
Adam Retter

eXist Developer
{ United Kingdom }
adam@exist-db.org
irc://irc.freenode.net/existdb
Received on Sunday, 3 January 2016 19:53:19 UTC

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