Re: Proposal: 6NF
Date: Wed, 04 Oct 2006 12:50:52 GMT
Message-ID: <M6OUg.80$cz.1594_at_ursa-nb00s0.nbnet.nb.ca>
[further irrelevancies snipped]
> You missed my point entirely. My point was that the physical models of
> 1 and 2 might as well be identical (accepting your comments about
> foreign keys, which are a logical issue). If the physical model is
> identical then there is no reason to suppose any difference in
> performance.
He's a self-aggrandizing ignorant. They are universally skilled at ducking points (and clues.)
>>The empty set does not contain a value; every non-empty set contains at >>least one value. Doesn't that imply that the empty set indicates the >>absence of a value?
>
> The empty set IS a value. Whether the empty set implies something or
> not depends on the interpretation the user puts on any proposition
> containing the empty set. It is still a value.
>
>
>>Use something similar to the empty set instead of SQL NULL. It would >>completely eliminate 3VL altogether. >> >>Some operators: >> >>Ø = Ø is TRUE >>x > Ø is TRUE unless x = Ø or x = +infinity >>x < Ø is TRUE unless x = Ø or x = -infinity >>x + Ø = x use the empty sum (0) >>x * Ø = x use the empty product (1)
>
> So Ø looks like some value of the domain in question. If all you are
> proposing is better domain support then I agree. Support for
> user-defined domains and operators is a far better alternative to
> nulls. Unfortunately the task of defining sensible results for such a
> value for every operator could be onerous. For that reason I think the
> technique of decomposition into separate relations still has its place.
I would not let the idiot off the hook quite so easily.
>>x > Ø is TRUE unless x = Ø or x = +infinity >>x < Ø is TRUE unless x = Ø or x = -infinity
So, if x is of a domain that is a total order, the additional 'value' renders it not an order at all. That's a loss that is not easy to accept.
>>x + Ø = x use the empty sum (0) >>x * Ø = x use the empty product (1)
Since when has voodoo mathematics ever benefited anyone? Consider:
(x + 1) * (Ø + 1)
= (x + 1) * (1)
= (x + 1)
(x + 1) * (Ø + 1)
= (x + 1) * Ø + (x + 1) * 1 = (x + 1) + (x + 1) = 2 * (x + 1)
How many C-level executives do you know who will accept a number that might be a billion dollars or might be two billion? (I mean other than at Enron.) Received on Wed Oct 04 2006 - 14:50:52 CEST