Re: So what's null then if it's not nothing?

JOG wrote:
[...]
> If you have an integer column, say, that allows nulls, its domain is:
> {I, Null} (where I represents the integers). While the integers were
> originally well ordered over the operators that SQL queries, now we
> have a Null element that is _incomparable_ to anything else in the set,
> yielding a poset. This to my mind makes a theorem like 3<Null invalid
> as the two items incomparable. My question is - is this not a stumbling
> block

Why would it be a stumbling block ? You may (a) not care about null ordering; (b) define such order independently of the '<=' predicate.

> before you even reach the point where one can debate whether a
> 3VL be layered on top? All best, Jim.
Received on Tue Dec 13 2005 - 17:01:06 CET