Re: Logical equivalence of simple and complex types under the relational model?
Date: 30 Nov 2004 15:54:37 -0800
Message-ID: <3638acfd.0411301554.579af4dd_at_posting.google.com>
neo55592_at_hotmail.com (Neo) wrote in message news:<4b45d3ad.0411301048.4a23356b_at_posting.google.com>...
> > It seems to me at first sight that
> > 1) RM with simple types
> > 2) RM with complex types
> > are indistiguishable at the logical level.
>
> What is a type? What distinguishes simple from complex?
[Quoted] A type is a set of values supporting the same operations. Sometimes `type' is further refined to require that all values in the type have the same representation.
I'm guessing that Rene is using simple and complex to mean primitive and compound respectively.
A compound type is one that builds a new type from other types; a primitive type is one that does not. For example, int, float and string are primitive, whereas array(float), list(string), tuple(int, list(float), char) etc. are compound.
- Ralph