Re: Constraints and Functional Dependencies

Cimode wrote:
> mAsterdam wrote:
> [Snipped]

>> But what exactly is the reference referencing?
>> A set of S-tuples, not just one.
>> That makes it a sort of hand_wave instead of a reference, right?
>>
>> Is there something I am missing?

> Maybe the preeminence of RA domain associative characterization over
> structuralist perspective based on attributes.

I need some help to decipher this.

>> <handwave>
>> (i a)
>>         A relation R with attribute a (written as R(a)) having
>>         a as a handwave into S(b)
>>         is expressed as follows:
>>
>>          forall R(a): exists S(b): a = b
>>
>>          Note that b need not be a ck to S, hence 'into', not 'to'.
>> </handwave>

> Again, attribute-based characterization of domains and relations leads
> to a conceptual dead end and a circular argumentation about key (As
> you can see).

I really don't know if I am reading this right.

I don't see circularity in Marshall's FD/ck expression. Do you?

> Pulling out of it requires effort. It seems however
> that this perspective and the proof of it ellludes some of the
> audiences. I do not know how to express it better than I did.
Received on Sun Feb 25 2007 - 14:07:17 CET