A Theory of Functional Dependencies for Object-Oriented Data Models.
Grant Weddell · 1989
We propose a more expressive form of functional dependency for object oriented data models. The generalization derives mainly from their common feature of combining the separate notions of domain and relation in the relational model into a single notion of class. This results in a richer terminological component for their query languages, in which a single term may traverse any number of properties, including none. A sound and complete axiomatization is presented for a simple choice of semantic data model in which classes can also be organized in a generalization taxonomy. Decision procedures are exhibited that apply when the dependencies included in a schema correspond to keys, or when the schema itself is acyclic. Finally, we outline several applications of the theory to various problems in physical design and in query optimization.