Re: Proposal: 6NF

"Marshall" <marshall.spight_at_gmail.com> wrote in message news:1160335298.815821.111740_at_m73g2000cwd.googlegroups.com...
> In my not-so-humble opinion, this whole thread is a bunch of
> useless talking-past-each-other. The word "null" (like all other
> words) means different things in different contexts, and "null"
> in particular means a variety of different, *incompatible* things.
> It seems to me that everyone is assuming it means the same
> thing to them as it does to the person they're talking to, at
> least some of the time.
>
>
> [context] term
> -----------------
> [math] empty set
> [SQL] null
> [3VL] unknown
> [Java] null
> [lisp] nil
> [C] pointer 0
> [type theory] bottom
> [SML] Maybe algebraic data type
> [Haskell] Maybe monad
> [Nested RA] value with an empty determinant-set functional dependency
> [TTM] Table Dum
> [TTM] omega
>
> ... and probably many more.
>
> Every one of these is a distinct concept, with distinct semantics.
> None of them can be separated from the underlying theory.
> It only makes sense to consider these within the context of
> the theory they are embedded in, and a direct comparison that
> doesn't take in to account how well the concept fits into its
> theory is leaving out important details. It is simply pointless
> to talk about one being better than the other without context.
>
> What we have to do instead is consider the context, consider
> the desired behavior, consider the possible failure modes,
> and measure the semantics of any given proposal within
> the context of a particular theory. We can't even do that
> without an agreed-upon set up use cases.
>
> I don't think we've got anything approximating consensus
> on what the desired behavior is.
>
> So: what is the desired behavior? What are the use cases?
>
>
> Marshall
>

Yes, but....

As far as I'm concerned, Roy nailed it.

null means "there isn't any data here... make of it what you will." Received on Thu Oct 12 2006 - 13:08:29 CEST