Re: Does Codd's view of a relational database differ from that of Date & Darwin? [M.Gittens]

mountain man wrote:
>
> The model cannot be complicated by essences of reality.

Since everything in reality can be described without them, I don't see how null values can be considered "essences of reality" under any reasonable definition of that term.

> In reality, information may be partial, and thus have elements
> in it which have null values.

You don't need null values to represent partial information.

> Modelling holes in information is straightforward
> with the use of nulls. You either have them, or
> you dont. You could probably replace then with
> a value, say x, but what would this gain?

It would keep the meta-model simpeler. But that's not the only way to model partial information w/o null values and in many cases the worst way to do it.

• Jan Hidders