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Re: XML storing and management

From: Jan Hidders <hidders_at_gmail.com>
Date: Thu, 27 Sep 2007 09:44:58 -0700
Message-ID: <1190911498.923039.151330@19g2000hsx.googlegroups.com>


On 27 sep, 16:27, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> Jan Hidders wrote:
> > On 27 sep, 02:19, JOG <j..._at_cs.nott.ac.uk> wrote:
>
> >>Ok, so why is it exactly cdt, despite the inherent flaws of a
> >>hierarchical model such as XML, it has seen such widespread uptake?
>
> > It's all hype, of course.
>
> > Btw., what fundamental flaws?
>
> Well, let's see... How about we start with: "The inability to re-order
> the data without changing meaning and without destroying information." ?

"Hierarchical models such as XML" are not necessarily ordered-only data models. In fact most proposals for semistructured data models before XML weren't.

But even in XML this is not a big problem. Whether reordering destroys information or not depends on your interpretation of the data. If you send me an XML document and in addition tell me that certain parts represent sets then I can reorder them without destroying any information. The fact that XML is an ordered data model only implies that it *might* destroy informaton, not that it *must*. There are ways to declare in languages such as XQuery that certain parts, or the whole tree, or certain final or intermediate results should be interpreted as unordered, so also that is not really a big or fundamental problem.

Of course, I'm not claiming that it could not have been better. I'd personally prefer it if there had been a standardized way of indicating unorderedness and that this would have been taken into account in query languages such as XQuery. But the fact is that up to now neither the people that are using XQuery in practice nor the people that are implementing XQuery have been listing this as their prime concern. And you can theorize as much as you like, but it is practice that decides whether something is really a fundamental or inherent problem or not.

Received on Thu Sep 27 2007 - 11:44:58 CDT

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