[Bug 4535] [UPD] Section 2.4.4 Rename: make it optional

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4535





------- Comment #5 from mike@saxonica.com  2007-05-13 20:48 -------
>a system that provides XML views over relational data

In the early days of the relational model, many people tried to implement
relational interfaces over a non-relational data store (this was the subject of
my PhD thesis back in 1975). Usually they were not able to implement the
relational model with 100% fidelity, and the industry was quick to define
conformance criteria (Codd's famous 12 rules) that would distinguish such
systems from those that were purely relational.

I think we are now in the same situation with XQuery. Systems that have a
relational data store underneath, rather than an implementation of the XDM data
model, will always have difficulty implementing some constructs, and this will
be particularly true of updates.

We shouldn't respond by lowering the conformance barrier: instead we should
recognize that such systems, while they will never have 100% fidelity to the
XML/XDM/XQuery model, nevertheless are a useful engineering approximation that
offers users significant transition and coexistence benefits.

Michael Kay

Received on Sunday, 13 May 2007 20:49:01 UTC