Detecting composite events in active database systems using Petri nets

The detection of events in an active database system turns out to be a difficult problem due to the expressive event specification languages proposed in the recent past which include, among others, complexly defined events (composite events). Therefore, a mechanism is required that is suitable to model the semantics of composite events and to implement the event detector. We demonstrate how Petri nets can be used as the basis of such a mechanism in the context of the SAMOS active database system prototype