A UNIVERSAL RELATION DATA MODEL WITH SEMANTIC ABSTRACTIONS

Two important features of modern database models are support for complex data structures and support for high-level data retrieval and update. The first issue has been studied by the development of various semantic data models; the second issue has been studied through universal relation data models. In this paper we examine how the advantages of these two approaches can be combined. We introduce a new data model, which incorporates standard concepts from semantic data models such as entities, aggregations, and ISA hierarchies. We then show how nonnavigational queries and updates can be interpreted in this model. The main contribution of this paper is to demonstrate how universal relation techniques can be extended to a more powerful data model. Moreover, the semantic constructs of our model allow us to eliminate many of the limitations of previous universal relation models.