Device is a system that integrates production rules in an active Object-Oriented Database (OODB) system that supports event-driven rules. Production rules are useful for several tasks of active database systems, such as integrity constraint checking, derived data maintenance, database state monitoring, etc. Furthermore production rules can express knowledge in a high-level form for problem solving in Knowledge Base Systems (KBS). Present active OODB systems traditionally provide event-driven rules, which are triggered by events, i.e. database modifications
