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Re: XML Schema question on key, keyref constraints

• To: Bob Foster <bob@o...>
• Subject: Re: XML Schema question on key, keyref constraints
• From: Murali Mani <mani@C...>
• Date: Thu, 27 Nov 2003 06:11:02 -0800 (PST)
• Cc: xml-dev@l...
• In-reply-to: <3FC5FCDE.2080802@o...>
• References: <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAAhCFAFVZZU0euzEhF1WD3e8KAAAAQAAAANVVzk3UcKk+ohCJvjGQdbQEAAAAA@f...><Pine.GSO.4.58.0311261114200.1123@p...> <3FC5BC7A.7090101@o...><Pine.GSO.4.58.0311270413030.7869@p...> <3FC5FCDE.2080802@o...>

> In the data model you laid out, moving the key and keyref to the
> ancestor (root) scope really don't buy you anything (even after you add
> the necessary state code to car).
>
> Key/keyref seem well-suited to describing elements that can be
> "flattened" into relational tuples, not so good for true hierarchies.
> I'm glad to hear HT and company are working the problem. Chained keyrefs
> sound like a useful and usable addition. (At least, they'll be usable
> after Priscilla explains them in the second edition of Definitive XML
> Schema. ;-)

yes, that is exactly what I was trying to reflect on: "relative keys"
(same as keys for elements that cannot be flattened to relational tuples),
are they useful??

chained keyrefs sound like correct, but are they really useful??? Do you
need to really go there, or can we just say that we define keyrefs only
for keys defined within the root scope..?? the question then comes is do
we really need keys that are not defined within the root scope..

Anyways, just random thoughts.. I tend to be tilting towards no need for
relative keys.. (though they are not really harmful)..

best, murali.

• References:
  • XML Schema (sequence) and MSXMLDOM question.
    • From: "Rodrigo Pinho Pereira de Souza" <rpinho@f...>
  • XML Schema question on key, keyref constraints
    • From: Murali Mani <mani@C...>
  • Re: XML Schema question on key, keyref constraints
    • From: Bob Foster <bob@o...>
  • Re: XML Schema question on key, keyref constraints
    • From: Murali Mani <mani@C...>
  • Re: XML Schema question on key, keyref constraints
    • From: Bob Foster <bob@o...>

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