Re: Impact of XML on Data Modeling

Original Message From "Michael Kay"...

>> If these observations are correct, my next question would be: Is the W3C
>> XML Schema the best choice on the market today for data modeling in the 
>> XML
>> world?  (why or why not)
>
> I think there are two difficulties in using XML Schema for modelling.
> ...
> The other is the focus on describing the structure of a particular 
> document
> type or message type. This is OK in situations where the document is the
> data. But in situations where the document is a message, a transient data
> flow between components of the application, it works less well, because 
> it's
> difficult to capture the areas of commonality between all those messages -
> there's some underlying data model and it's only distantly related to the
> structure of all the messages that are flying around.

I may of misunderstood, but...  that doesn't mean that XML schema isn't 
useful for defining the messages themselves though.  The schemas used to 
define the 'application' data model will no doubt be different to the 
schemas used to define the messages passing between nodes using the data 
model.

In fact, if you are just talking messages, there may be no defined 
'application' data model at all (at least not an XML based one).  Protocols 
such as VoIP and HTTP are generally defined mainly in terms of the messages 
that flow between nodes.

Regards,

Pete Cordell
Codalogic
Visit http://www.codalogic.com/lmx/ for XML C++ data binding