Re: Logical equivalence of simple and complex types under the relational model?

"Alfredo Novoa" <anovoa_at_ncs.es> wrote in message news:9vpsq0t18jgv0dkm2mq7udsefqjbhr6p69_at_4ax.com...
> On Tue, 30 Nov 2004 23:33:51 +0100, "Rene de Visser"
> <Rene_de_Visser_at_hotmail.com> wrote:
>
>>What exactly do you mean by "if it needs the help of the type system to
>>decompose the value, its a simple value"?
>>
>>How do you know if the relational system is "using the help of the type
>>system"?
>
> IMO Paul is trying to save the concept of "atomicity", but he is
> breaking other things in the attempt.
>
What is he breaking?

> "Atomic" can not be defined precisely and that's all.

"Not decomposable by the DBMS" seems precise enough as a concept or notion to me.

I find it disturbing that some would call Codd's definitions of a formal model "outdated" or "incorrect". If anything, Codd hasn't wobbled back and forth on nested relations as attributes or updateable views like other leading relational experts, who in some individuals' opinions, seem to be unassailable in logic and argument, all of this despite rather minor inconsistencies in conclusion over time.

• Dan