RE: [xml-dev] Are people really using Identity constraints specified in XML schema?

["Cox, Bruce" <Bruce.Cox@USPTO.GOV>]

Are business rules semantics?  I take that question to mean that some
business rules can be fully automated since they are about properties of
data that succumb to, for example, XML Schema data typing, while others
are more problematic and may require methods not easily automated.  In
the case of patent document numbers, the goal would be to "ensure shared
data is recognized" and only then processed for the current purpose. 

I certainly appreciate the benefit of using DTDs with their lack of
content validation.  Without that characteristic, it is unlikely that
the patent offices of the world would have agreed on a common vocabulary
for patent applications and publications.  Now that we are on the verge
of exchanging instances internationally, that characteristic may bite us
by impairing interoperability due to significant variances between the
start and end tags for any given element.

Document numbers are a special case, in that they are critical to
establishing the relationship among patents filed and granted in
different countries.  Accuracy is sufficiently important to be spending
millions of USD a year to correct bad numbers provided by applicants or
other offices.  In this one case, I hope there is some way to express
the validation rules independently of custom code so that we can
describe the rules to each other unambiguously and implement them
consistently.

With XML Schema data typing, followed by Schematron, what would come
next to cover the residue?  I don't think anything to do with document
numbers can't be automatically validated.

Bruce B. Cox
SA4XMLT
+1-703-306-2606

-----Original Message-----
From: Bullard, Claude L (Len) [mailto:len.bullard@intergraph.com] 
Sent: Tuesday, August 17, 2004 9:26 AM
To: Cox, Bruce; Roger L. Costello; xml-dev@lists.xml.org
Subject: RE: [xml-dev] Are people really using Identity constraints
specified in XML schema?

Good.

http://hbsworkingknowledge.hbs.edu/item.jhtml?id=4318&t=leadership

There is a snarky habit on some lists and in some discussions of dissing
the XML-Dev habit of debating issues, some even non-XML related.
XML-Dev is one of the most consistently useful and informative lists
precisely because of this.

1. The designer has a variety of options of where to put business rules.
Are business rules semantics?

2. What situational aspects determine where it is best to put these?
Some will argue that it is seldom best to put them in the schema because
in a data-centric system, business rules act as the interpreter of the
data and given several independently managed vertical semantic stacks,
the first order of business is to ensure shared data is recognized, and
then handled.

DTDs were successful because they did less of the latter. 
XML Schema, applied without some notion of independence, does too much
of the latter.  RELAX NG is more constrained in what it can do, so it
artificially restricts this 
application.   However in all cases, it is not the 
technology but the application design that is in question.

In CAD-to-CAD communications, we find that keeping the shared data
description as simple as possible and avoiding the issues of command and
control work best even though dispatch is essentially a command and
control application. 
This is the distributed vs centralized issue that comes up again and
again in the 911 hearings and in most 
situated network designs.   Collaborative networks have 
aspects that are similar to the problems described in the article cited
above.

len