Applying Petri Nets in Active Database Systems

Reactive behavior of active database systems is achieved through the definition of event-condition-action (ECA) rules. Generally, ECA rule representation and processing are separated in the majority of existing active database systems. In this paper, we propose a conditional colored Petri net (CCPN) approach to model and simulate ECA rules. CCPN can not only integrate rule representation and processing in only one model, but is also independent of the actual database system. Furthermore, we have developed a software platform named ECAPNSim, which can generate a CCPN model automatically from a text file of ECA rule description, and communicate with a traditional database system when an event is detected from the database or an action command is generated by the CCPN simulator.