The activation of active rules in the heterogeneous database systems

Active rules have been widely used in the modern database systems. They have provided a great contribution to the maintenance of data integrity and data consistency in database systems. They also enable the system to become active instead of passive which traditional databases do. In passive databases the queries or transactions are executed only when explicitly requested by users. Active databases contain the capability to automatic monitor the conditions which defined over the database state and the ability to take an action when the state of the underlying database changes. This paper investigates how the active rule can be triggered in a heterogeneous database system environment.