Re: RM formalism supporting partial information

On Nov 18, 11:50 am, paul c <toledobythe..._at_ooyah.ac> wrote:
> David BL wrote:
>
> ...
>
>
>
> > If you're working directly with the tuples, then in a way you're
> > working at a more physical level than if you're using a difference
> > operator to remove information. ...
>
> I wasn't expecting that you'd say tuples are physical, not to any degree
> at all. For example, I don't see why one would take, nor need to take,
> D&D's tuple definition which uses a set of triples, and physically store
> it. But that tuple definition is certainly necessary for their logical
> set operations. Are you suggesting that information can be removed by
> other than a difference operator such as D&D's which is simply {original
> relation} <AND> ( <NOT> {relation to be "removed"})?

I don't want to imply that tuples be physically represented - I guess it was a poor choice of words.

I'll say it this way: When one admits multi-valued attributes under my proposed interpretation the non-uniqueness of representation raises question marks over the significance of individual tuples.

The more practical problem is that users that don't appreciate the model will look at a tuple and think they can deduce negations of predicate instantiations. Received on Mon Nov 19 2007 - 02:11:25 CET