>Yes, it's true there's a "conceptual" element in the thing. But the main
>use of domains is to package a set of data attributes (type, size,
>constraints) into a re-usable bundle. It doesn't matter if (as in the
>simple example above) you define more than one domain with the same set of
>attributes. If their contextual use is different, it might be
>justified. You can add more constraints to a domain, as long as they won't
>be violated by any data already using the domain.

Ja, I have recently started using domains (I've never really seen the need
for them before - *embarrassed grin* - and am finding them exceptionally
useful for this very thing.

For example, every one of my tables has a field called "recordno", which is
an integer field that also forms the primary key.

So I just define a domain RECORDNUM INTEGER NOT NULL and bingo - I enforce
the same rules wherever I use it. There are other examples as well.


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