Extending a Commercial Object-oriented Database Management System with Capabilities for the Execution of Business Rules

This thesis presents the development of a Task Manager which handles a database schema that is automatically translated from the conceptual level to a data model of an active object-oriented database system. On the conceptual level the database schema to be handled is described with situation/activation diagrams. The Task Manager is implemented as a singleton which is started once and carries on in its life-cycle loops continuously. The single stages of the Task Manager stand for a certain amount of operations which are handled in detached processes. Different types of tasks are handled and executed at different stages of this life-cycle. Rules which are based on the event-condition-action paradigm propel the Task Manager's life-cycle. The active object-oriented database system TriGS (= Trigger system for GemStone) permits the registration and execution of such rules. TriGS per se represents an extension of the commercially available database system GemStone. Depending on their type, the tasks which are registered with the Task Manager are handled and executed in a semantically different way. If certain task conditions are met then the task's activity pushes the receiver object to the next stage of its life-cycle. This may lead to the possible occurrence of database inconsistencies which are perceived and reported by rules that are registered with TriGS.