Supporting a Semantic Data Model in a Distributed Database System

Existing distributed database systems are based mostly on the relational model. Furthermore, it has been argued that the relational model is the model best suited for distributed databases. This paper describes an implementation approach for supporting logical pointers between distributed entities. This apprdach is being employed in a distributed database system that supports a semantically rich data model and that currently is under implementation. The access structures used to support entity-toentity pointers in this data model facilitate the maintenance of referential integrity across sites. At the same time, they provide efficient access paths for distributed query processing. To make use of these access structures the extensions required of existing query processing techniques are quite straightforward. The research reported in this paper is supported jointly by the Advanced Research Projects Agency of the Department of Defense (DARPA) and the Naval Electronics Systems Command (NAVELEX) unaer contract NO0039-82-C-0226. The views and conclusions contained in this paper are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of DARPA, NAVELEX, or the U.S. Government.