Re: Lucid statement of the MV vs RM position?

paul c wrote:
> An example that some may not find very interesting, ie., too simple but
> still troubles me might be "the sets/combinations of parts that a
> supplier will agree to ship" having no other attributes than S# and P#,
> eg., SP { S#, {P#}} where I'm intending {P#} to mean a set of parts. I'm
> interested to know of the other writers or what they say.

The standard examples of Date & co. is relvars and their keys, and (iirc) functional dependencies. Those two both involve set-valued attributes, and they can't be "flattened" without losing information (unless you introduce an identifying attribute for each set). Your example is equivalent, I think. Anyway, isn't that you on the TTM list? You should know about Darwen's group-ungroup normal form, then.

-- 
Jon