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RE: about the "missing" axes in XQuery

From: Kay, Michael <Michael.Kay@softwareag.com>
Date: Fri, 18 Jul 2003 22:21:19 +0200
Message-ID: <DFF2AC9E3583D511A21F0008C7E62106073DD00D@daemsg02.software-ag.de>
To: jan.hidders@ua.ac.be, www-ql@w3.org
> 
>   Why are there axes missing in XQuery?
> 
> I would assume this was to keep the language simple, but it 
> seems to me that many optimization tricks that are known for 
> these missing axes become more difficult or even impossible 
> if the user has to simulate them. So not having these axes 
> makes query optimization actually harder. So why are they not 
> in there?

Certainly, the argument I have heard most often for omitting them is that
it's difficult to optimize them (or to do static type inferencing, which
some people consider as being almost equivalent to optimization). I share
your views, but the reason that they aren't in there is that there are other
people who don't. Just keep pushing...

Michael Kay
Received on Friday, 18 July 2003 16:21:28 UTC

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