DERIVING INCREMENTAL PRODUCTION RULES FOR DEDUCTIVE DATA

We show that the production rule mechanism provided by active database systems can be used to quickly and easily implement the logic rule in terface of deductive database systems. Deductive rules specify derived relations-using Datalog with built-in predicates and stratified negat ion; the deductive rules are compiled automatically into production ru les. We present a materialized approach, in which the derived relation s are stored in the database and the production rules automatically an d incrementally propagate base relation changes to the derived relatio ns. We also present a non-materialized approach, in which the producti on rules compute the derived relations on demand.