A Petri Net Model For An Active Database Simulator.

Abstract

Active database systems were introduced to extend the database functionality. As well as a repository of data, active database can detect the occurrence of events in a database system and react automatically to event occurrence and execute certain actions either inside or outside the database. This behavior is specified by means of ECA (event-condition-action) rules, i.e., when an event has occurred, if the condition is evaluated to true, then an action is executed. In this paper a simulator for active databases, named ECAPNSim, is described. ECAPNSim uses the definition of ECA rules like a structure of an extended Petri net model, the Conditional Colored Petri Net (CCPN). Conditional Colored Petri Net definition involves the knowledge and execution model, which describe the features that an active database system must have. An example has been developed in order to show the ECAPNSim applicability in a certain study area.