Database integration in a distributed heterogeneous database system

This paper describes the approach to database integration in a heterogeneous distributed database environment utilized by the Amoco Distributed Database System (ADDS). We start with the definition of the extended relational data model that is used by ADDS for database integration. We demonstrate various aspects of resolving possible data conflicts occurring in the database integration process. The ADDS query and data definition languages are defined and their expressive power is discussed. We conclude with presentation of a query conversion algorithm to convert a user data request into a set of queries against supported physical databases.