Parallel architectures and object-oriented databases

Research into object-based concurrency and parallel architectures is briefly described. A multiprocessing, object-oriented database programming language and environment called RAPP has been designed and implemented, and is based on a tight integration of the relational data model and the object-oriented data modeling facilities of a modular, multiprocessing programming language. Persistence is provided through the relation data type, and so the simplicity of the relational model is retained. However, attributes of relations may be of type class, thereby permitting the implementation of a wide variety of object-oriented data modeling constructs, including aggregation and generalization, and complex objects with shared subobjects. Classes in RAPP support data abstraction, encapsulation, and multiple inheritance. Concurrency is provided by means of an explicit database transaction mechanism coupled with built-in primitives for synchronization, transaction atomicity, and serializability. The system consists of a relatively small, well-structured, multipass compiler which generates P-code and a highly portable run-time support environment