Re: Pizza Example

Eric Kaun wrote:
>
> OK, I expressed myself badly. Logically, the relational user sees values in
> relations. The types of those values can be anything, including lists and
> such, but there shouldn't be operators in the data model to manipulate
> those - rather, those are user-defined operators for the specified types.

So, one would expect that the NEST and UNNEST operators of the nested relational algebra would not be allowed, wouldn't one? I know I would. What else could "logically expose" mean for a relation-valued column? Or the nested relational calculus, which doesn't have such operators, but still allows you to operate on (and combine) the nested sets, would that be Ok?

> Is that better? Date's paper "What First Normal Form Really Means" talks
> about this in great detail...

Ah, well, let me say here and now that I'm not a big fan of Chris Date, to put it mildly, and the arrogance of dbdebunk makes me physically sick. I know the paper you refer to, and I find it rather unconvincing.

• Jan Hidders