Re: Proposal: 6NF

Cimode wrote:
> dawn wrote:
>
> > Given the definition of NULL that I typically use (with non-SQL based
> > solutions), NULL is a value and can be modeled mathematically with the
> > empty set. In that case, a relation tuple with a NULL is as valid
> > mathematically as one without. Agreed? --dawn
>
> An ultra high level density of bullshit and confusion packed in few
> sentences...
>
> The fact a construct can be modeled mathematically does not mean it
> systematically qualifies it as a value. The *ONLY* valid mathematical
> definition of a *value* consist of having the characteristic of being
> the output of a *predetermined* transformation (function).

Define a function f such that f("F") = "Female" and f("M") = "Male" and f(null) = null

Functions like this are very common when working with 2VL languages.

> NULLS are a pure input. Nothing can be said of the transformation OR
> the output and certainly NOT that it could be NULL.

Again, that depends on your definition of NULL. I don't understand how you would not think it depends on your definition. Do you think these letters fell from the sky with a meaning attached?

>
> Not convinced? I dare you to produce/define ANY function that certainly
> produces NULL as an output. If you can't then just shut the hell
> up...and stop confusing people...

I did produce one. If you would like to see it in action, you can use the open source dbms OpenQM. Remember, this is NOT an SQL NULL. OpenQM does not support SQL.

> OTOH, one can produce several functions that produce an empty set as an
> output. An empty set is therefore a value.

And guess what? The languages packaged with OpenQM will treat NULL in their logic as if it were the empty set.

> After that logical demonstration and all the arguments presented, if
> there is still a chance that you or anybody believe that NULL is a
> value

this is not part of a belief system, but part of a defined system. You might work with a system that treats a NULL as the lack of a value while I do not.

> that can only mean one thing: that you simply can not or do not
> want to build logical and sound reasonning.

Guess again, brother. --dawn Received on Sat Oct 07 2006 - 00:20:43 CEST