Re: Complete axiomatization of relational algebra

"Drieux...just Drieux" wrote:

> Jan Hidders wrote:
> >
> > Does anybody know if there is a complete algebraic axiomatization of the
> > relational algebra (as used in relational database theory) or a proof
> > that such a thing is not possible?
> >
> > --
> > Jan Hidders
>
> There have been papers published on this, of which I'm sure you're
> aware. You might want to have a look both at xxx.lanl.gov and at the
> Hypatia on-line library.
>
> I'll look through my own files; my research area is category theory, and
> I'm a practising consultant dealing with VLDB and VLDW problems. I've
> seen approaches to this topic, but the actual reduction to an axiomatic
> basis, if it was done, has eluded me.

Here is one way of approaching this question.

If we are just talking about a set of tables each identified as some sequence of properties that take values as rows and that sequence repeated as rows, and with some properties from table to table whose values are associated as keys or pointers, then this arrangement may be converted to a single set of elements each having a uniform set of properties. I.e., we should be able to `denormalize' to a single table. The primary operation on this table is to ask what rows have some set of property values that consists of set intersection and union. The operation identifies which rows satisfy, say, some conjunctive (disjunctive) normal form of monadic predicates, and where each predicate is on a particular property.

Regards,

Neil Nelson Received on Sat Feb 17 2001 - 03:17:51 CET