Sergio Andreozzi wrote:
The aspect of extensibility is secondary to this and is present because is a requirement from many parties. The fact that the abstract GLUE Information Model (represented using the object-oriented constructs of UML Class diagrams) is rendered on different concrete data models (XML Schema, relational and LDAP) makes it difficult to delegate at the concrete data model level the extensibility aspects. "Hooks" are currently present at the information model level and can be used to advertise information that is not currently captured by the specification without waiting for a new spec version. The GLUE Spec is deliberately not rigorous in defining the format of the content of the extensibility points.
My point was that the information model should state what (in general) the information is (e.g. a set of properties) without stating the format of that information (which is the data model's job). At least back in the GLUE session in OGF21 those two aspects were a bit mixed up. (Or at least as far as I could see at the time; I may have got a false impression. :-)) This isn't to say that the data model shouldn't be worked on. Just that the split between the two is important. Donal.