Re: Proposal: 6NF
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 06 Oct 2006 23:24:05 GMT
Message-ID: <pABVg.101394$5R2.73994_at_pd7urf3no>
>> 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).
Date: Fri, 06 Oct 2006 23:24:05 GMT
Message-ID: <pABVg.101394$5R2.73994_at_pd7urf3no>
dawn wrote:
> 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.
> ...
No they aren't. You are talking of something other than 2VL. You won't get anywhere if you don't start out right.
p Received on Sat Oct 07 2006 - 01:24:05 CEST