XML.orgXML.org
FOCUS AREAS |XML-DEV |XML.org DAILY NEWSLINK |REGISTRY |RESOURCES |ABOUT
OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index]
Re: [xml-dev] Notable declarative expressions?

Mike,

I generally agree with what you said, with one exception.

You asked "What else does it have to be to make it a data model?"

In my education, a data model incorporates the operations/functions/behaviors (OFBs) for the things described by the model. In the relational model, for example, the various OFBs of relational algebra (cross product, projection, filter, grouping, etc.) and relational calculus (e.g., relational division) all form an important part of the model.

Hope this helps,
Jim


On 2016-12-20 11:04, Michael Kay wrote:
On 20 Dec 2016, at 17:57, Thomas Passin <list1@tompassin.net> wrote:

I think you could (or at least I could) think of a schema as a model.
I'm inclined to agree. It's at least as much a data model as the schema of a relational database is. It defines a value space, and it provides mechanisms for documenting the relationships between values in the value space and things in the world outside. What else does it have to be to make it a data model?

The fact that XSDs primary mechanism for constraining the value space is by means of a grammar is a distinguishing feature, but I don't see anything in the theory of data modelling that says "the constraints on the value space must be defined using mechanisms other than grammars".

Michael Kay
Saxonica
_______________________________________________________________________

XML-DEV is a publicly archived, unmoderated list hosted by OASIS
to support XML implementation and development. To minimize
spam in the archives, you must subscribe before posting.

[Un]Subscribe/change address: http://www.oasis-open.org/mlmanage/
Or unsubscribe: xml-dev-unsubscribe@lists.xml.org
subscribe: xml-dev-subscribe@lists.xml.org
List archive: http://lists.xml.org/archives/xml-dev/
List Guidelines: http://www.oasis-open.org/maillists/guidelines.php

--
========================================================================
Jim Melton --- Editor of ISO/IEC 9075-* (SQL)     Phone: +1.801.942.0144
  Chair, ISO/IEC JTC1/SC32 and W3C XML Query WG    Fax : +1.801.942.3345
Oracle Corporation        Oracle Email: jim dot melton at oracle dot com
1930 Viscounti Drive      Alternate email: jim dot melton at acm dot org
Sandy, UT 84093-1063 USA  Personal email: SheltieJim at xmission dot com
========================================================================
=  Facts are facts.   But any opinions expressed are the opinions      =
=  only of myself and may or may not reflect the opinions of anybody   =
=  else with whom I may or may not have discussed the issues at hand.  =
========================================================================



[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index]


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 1993-2007 XML.org. This site is hosted by OASIS