This paper describes a system which allows distributed access to the data in a persistent store. Our approach to enabling access to a single store from different Persistent Java programs is based on Distributed Shared Memory techniques. Persistent programs require no changes to operate with the new system and are able to interact with the store regardless of its location. The advantage of allowing many programs to access the store at once is that such a system can be scaled to allow many programs to run simultaneously.
The crucial problem with having potentially two programs accessing the same objects is that they be able to do so coherently. Our approach ensures that objects are not written to simultaneously, and that up-to-date copies of an object are always available to a program reading that object.