[sc34wg3] Conformance

Lars Marius Garshol sc34wg3@isotopicmaps.org
27 Apr 2003 15:53:22 +0200


* Jan Algermissen
| 
| For me "the same abstract structure...in the form of a data model."
| means that N0396 defines a 'conceptual data model' or call it
| 'abstract information structure'.

I agree with the latter. The first I don't know what is. I'd be very
careful with that term, since it seems to conflate two different kinds
of models into a single one.
 
| What I am up to is to find the purpose that this structure
| fulfills. Since it does not make sense to use it to constrain the
| internals (I could create an implementation that never actually
| performs a merge internally but makes it look as if it did from the
| outside) then what is it good for (not the SAM as a whole, just the
| data structure)?  Is it purely a matter of providing a language to
| 'say' the important stuff (e.g.  merging rules)? Is it purely
| illustrative?

I explained this to you in the email you just replied to:

* Lars Marius Garshol
|
| The SAM is *not* a conceptual model, it's the instrument we use for
| defining the interpretation of the two syntaxes, the relationship
| between them, and we will also use it to define a conformance testing
| tool (CXTM), and finally it will be the foundation of the constraint
| and query languages.

Isn't this clear? N0278 and N0323 say the same thing.
 
| To take this out of TM context: What purpose does the entity
| relationship model fulfill in RDBMS land?

It's the mathematical foundation of the ER modelling formalism, which
is intended to help people produce better information models. The ER
model is used to connect ER diagrams to the relational data model.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >