On 20 nov, 00:41, paul c <toledobythe..._at_ooyah.ac> wrote:
> paul c wrote:
> > Marshall wrote:
> > ...
> >>> The important concepts are tuples, propositions, predicates etc.
>
> >> For myself, I have found less and less use for the concept
> >> of tuple over time. I try as much as possible to do everything
> >> with just relations. Relations as sets-of-propositions, relations
> >> as predicates, cardinality-1 relations instead of tuples, etc.
> >> In fact I am going so far as to attempt the idea of a theory with
> >> relations as the only primitive. (And possibly also including
> >> scalars.)
>
> >> Not 100% clear if the idea can be carried out all the way, but
> >> it's promising so far.
>
> > (Forgot to ask this before). I notice that D&D depend on tuples to
> > define their GROUP operator. Is there a way to define a Grouping or
> > group-by operator with tuples?
>
> Oops, I meant to say "is there a way to define them without tuples?".
How about an attribute, a domain and a relational division?
Received on Fri Nov 23 2007 - 15:33:36 CST
