Development of Rule Scheduler for Multiple Triggered Rules in Active Object-Relational Database Systems
Active object-relational database management systems (ORDBMS) react to the occurrence of predefined events automatically by the definition of Event-Condition-Action (ECA) rules. Whenever an event occurrence causes the triggering of multiple rules at the same time, the execution model of an active ORDBMS requires an explicit trigger rule conflict policy which regulates the selection and execution of multiple triggered rules. The rule execution model provide a mechanism known as rule scheduling which performs the ordering and execution semantics of multiple triggered rules to handle the trigger rule conflicts. Conventional rule schedulers have been developed to execute the multiple triggered rules sequentially based on system defined priority. However advanced applications require a rule scheduler to support both sequential and concurrent execution of multiple triggered rules based on static priority mechanism in active ORDBMS. Thus the objective of this research work is to develop an effective rule scheduler for executing multiple triggered rules both sequential and concurrent based on user-defined priority scheme.