RE: [xml-dev] RE: Caution using XML Schema backward- or forward-compatib

["Costello, Roger L." <costello@mitre.org>]

Hi Len,

> Was there a point to that other than to beg
> the use of semantic web tech for web services?

No, I am not pushing any semantic web techniques. WSDL documents focus
on describing a web service based on the syntax of the data.  For a
client to use a web service, it needs to also know the semantics.
There are many ways to describe the semantics.

> May I assume that the entire focus of this is not versioning for data
> exchange, but versioning for applications implemented AS web services
where
> the definition of web services has X Y and Z components?

Yes, I narrowed the problem to data exchange between a web service and
clients, where the clients are unknown to the web service (the web
service is available to anyone).  How clients use the data retrieved
from the web service is variable and unknown.  

The issue is: how is versioning related to validation?  

I assert that a data versioning strategy should be decoupled from a
data validation strategy.  Versioning should be driven by business
requirements, not technology limitations.

Your thoughts?

/Roger
 

-----Original Message-----
From: Len Bullard [mailto:cbullard@hiwaay.net] 
Sent: Monday, December 31, 2007 10:47 AM
To: Costello, Roger L.; xml-dev@lists.xml.org
Subject: RE: [xml-dev] RE: Caution using XML Schema backward- or
forward-compatibility as a versioning strategy for data exchange

Umm..  cool but you just restated pretty much the nut of the
discussions for
the design of XML originally.  Was there a point to that other than to
beg
the use of semantic web tech for web services?

A lot of applications don't need it.

May I assume that the entire focus of this is not versioning for data
exchange, but versioning for applications implemented AS web services
where
the definition of web services has X Y and Z components?

len


From: Costello, Roger L. [mailto:costello@mitre.org] 

A web service may also make artifacts available to clients to assist
them with "understanding what they get":

(a) A document (or documents) to help clients understand the data they
retrieve

There are many technologies to achieve this, including prose (i.e.
create a web page that client developers can read), data dictionary,
RDF/S, OWL.