Abstract:
One dilemma in the database community is the great variety of data models existing. We define an abstract data model that captures most of the relevant data models depending on the underlying type system. An algebraic foundation for the investigation of dependencies is presented similar to the one which is easily available for the relational data model (RDM). This may lead to a unifying dependency theory. A generalisation of Armstrong's Axioms for the implication of functional dependencies in the RDM to our abstract data model is given. The inference rules look similar to Armstrong's original axioms, thanks to the algebraic framework. The completeness result, however, requires a much finer analysis of the inference rules than in the RDM.