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_at_pd7urf2no>
>
> 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.
> ...
Date: Fri, 06 Oct 2006 23:29:29 GMT
Message-ID: <tFBVg.100563$1T2.19259_at_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 Sat Oct 07 2006 - 01:29:29 CEST