Re: Proposal: 6NF

From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 06 Oct 2006 23:29:29 GMT
Message-ID: <tFBVg.100563$1T2.19259@pd7urf2no>

Hugo Kornelis wrote:
> On Fri, 06 Oct 2006 08:32:36 GMT, Brian Selzer wrote:
>

>> "JOG" <jog_at_cs.nott.ac.uk> wrote in message 
>> news:1159970386.339044.87090_at_i42g2000cwa.googlegroups.com...
>>> Brian Selzer wrote:
>>>> "JOG" <jog_at_cs.nott.ac.uk> wrote in message
>>>> news:1159954091.119164.155490_at_m73g2000cwd.googlegroups.com...
>>>>> All of your points represent a wild goose chase in my eyes Brian. A
>>>>> proposition with a NULL in it is no proposition at all. From a logical
>>>>> perspective, case closed. A relation tuple with a NULL in it is no
>>>>> relation tuple at all. From a mathematical perspective, case closed.
>>>>> Trying to invoke the 'kludge perspective' is hardly going to convince a
>>>>> theoretical newsgroup.
>>>>>
>>>> Is the empty set a value?  Yes, it is.  So why can't a null be?
>>> Because an empty set is a value and a NULL is not.
>>>
>> Why not?

>
> Hi Brian,
>
> Because relational databases supporting NULL *define* it as a marker
> denoting the absence of a value. Dawn actually makes a good point about
> context: in C for instance, NULL has a completely different meaning.
> ...

Since it has a different meaning in C, there is no point bringing C into play here.

p Received on Fri Oct 06 2006 - 18:29:29 CDT