Re: Picking the Tools

[Christian Nentwich <c.nentwich@cs.ucl.ac.uk>]

> Unfortunately, I think we're stuck in a crease here.  UML is not
> expressive enough to model whatever we'd want to in XML/RDF/TM, etc., but
> it does have mature tools and strong adoption.
> So understandably you ask whether one should just use UML and therefrom
> generate the appropriate low-level formats.  I point out that UML is not
> expressive enough, that mechanical conversion from UML in any case would
> tend to poor results, and that hands-on conversion would be as much effort
> as just doing the modeling in the low-level formats to begin with.

There is no need to do hands-on conversions and I don't quite see why
mechanical conversions necessarily lead to poor results. The XMI
standard defines quite clearly how to turn a MOF-compliant metamodel
into a DTD. 

I have seen several approaches now to turning UML models into DTDs,
including approaches used by large organisations. Experienced developers
are much more at ease with data modelling in their preferred language. 

One should not forget that if someone models their data format in the
UML, they are interested in storing exactly the information that they
are modelling, no more. They are probably interested in making objects
persistent. If that's all they need, the job can be done using the UML.
No need for sophisticated schema mechanisms.

Christian