Mapping a semantic database model to the relational model

Abstract

The connection between semantic database models and the relational model is formally investigated using the Iris Data Model, which has been implemented using relational database techniques. The results focus on properties of relational schemas that are translations of Iris schemas. Two new types of constraints, cross-product constraints and multiplicity constraints are introduced to characterize the relational translations of Iris schemas. The connection established between Iris and relational schemas also yields new, unexpected information about Iris schemas. In particular, a notion of equivalence of Iris schemas is defined using their relational translations, and a result is obtained on simplifying the type structure of Iris schemas.