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From: Kay, Michael <Michael.Kay@softwareag.com>
Date: Wed, 16 Jul 2003 19:59:39 +0200
Message-ID: <DFF2AC9E3583D511A21F0008C7E62106073DCFFF@daemsg02.software-ag.de>
To: Norman Walsh <Norman.Walsh@Sun.COM>, Stephen Buxton <stephen.buxton@oracle.com>
Cc: public-qt-comments@w3.org
> / Stephen Buxton <stephen.buxton@oracle.com> was heard to say:
> | *Data Model, **Section 1, Introduction. *The distinction 
> between data 
> | model and value in the second paragraph is good, but I 
> think a third 
> | concept should also be introduced and given a name. This 
> third concept 
> | is the set of all values currently under consideration during the 
> | execution of some processor (XSLT, XQuery, etc.) using the 
> data model. 
> | A possible name for this concept is "data set". Thus the three 
> | concepts are:
> |
> | "data model" - the abstract framework specified by this 
> specification 
> | "data set" - a concrete realization of the data model at a 
> particular 
> | point in the execution of a processor "value" - a value in 
> a data set.
> I'm not sure I understand your comment. Are you suggesting 
> that the term "data set" should be defined for a concrete 
> instance of a data model? Where would this term be 
> referenced? (I don't see any value in defining the term if it 
> isn't referenced.)

I think Steve's point is a very good one. We often slip into talking about a
"data model" when we mean a "data set". For example, section 2.2.1 of the
latest XPath (internal) draft is titled "data model generation" - the very
title shows the problem, and it occurs again throughout the section.
Sometimes we use "data model instance", but it's not entirely clear what we
mean by the term.

It would be very awkward if we didn't have the word "relational database"
and instead always referred to it as "an instance of the relational data
model", or worse, as "a relational model". I'm not quite sure about Steve's
proposed definition, though.

Michael Kay
Received on Wednesday, 16 July 2003 14:01:00 UTC

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