Termination and confluence by rule prioritization

An active database system is a DBMS endowed with active rules, i.e., stored procedures activated by the system when specific events occur. The processing of active rules is characterized by two important properties: termination and confluence. We say that the processing of a set of active rules terminates if, given any initial active database state, the execution of the rules does not continue indefinitely; it is confluent if, for any initial database state, the final state is not influenced by the order of execution of the rules. Finding sufficient conditions for these properties to hold is a nontrivial problem, and the lack of a structured theory for the design of a system of active rules makes the analysis of the two properties more difficult. In this work, we translate a set of rules from any of the existing systems into an internal format; then, we translate the active rules into logical clauses, taking into account the system´s execution semantics, and transfer to the active process known simple results about termination and determinism available in the literature for deductive rules.