Re: 1 NF

On Mar 2, 4:54 am, "JOG" <j..._at_cs.nott.ac.uk> wrote:
>
> * Using a mathematical relation means that all the propositions
> collected in that set have to have the exact same structure.

Lately playing with ideas about constraint systems I've been toying with the idea that we could dispose of types as a *requirement* and make them optional, the same way that constraints are optional. However on further examination, it became clear that "having the same structure" was not a requirement that could be removed. In other words, we can get rid of column types and still have well-defined semantics, but we must retain the idea of a relation type, and that type must constrain what attributes the elements of the relation have, even if it doesn't constraint the values that elements' attributes have.

This seems very much like what you're saying.

Marshall Received on Fri Mar 02 2007 - 16:35:14 CET