Language Design Issues in Supporting Process-Oriented Computation in Persistent Environments

The problems of shared access to large bodies of information raise difficulties in the understanding and semantics of concurrency, distribution and stability. When the information is held in a persistent object store, these difficulties of understanding are extended to the interaction of the concepts of persistence and store with those above. Some of the difficulty is in deciding at what level the architecture or language operates, be it hardware or software. Other difficulties arise in the complexity of the problems of concurrency.
In this paper we identify these difficulties and clarify them with regard to database programming language design. We propose a model of concurrency that may be used as a solution to the problems. It is based on the rendezvous of Ada and integrated with a polymorphic type system with inheritance. This yields a process- oriented approach to system construction that has much in common with the object- oriented approach. We will demonstrate the facilities of the language Napier which allows the integration of these two methodologies along with a persistent environment to provide concurrently accessed object-oriented databases.