Entity-relationship database support for real-time adaptation

The authors describe an extended entity-relationship database designed to support the programming and execution of adaptable real-time applications. Specifically, they examine the E-R database that is part of CHAOS (concurrent hierarchical adaptable object system), an object-oriented programming and adaptation system. The adaptation control system in CHAOS, responsible for monitoring the execution environment, detecting the need for adaptations, and enacting selected adaptations, is structured around this extended E-R database. The authors outline the design of the E-R database, the mapping of objects and their attributes into it, the mechanisms for performing adaptations, and the database manipulation language interface to the database. Adaptations on application software are encoded in DML