Deductive and Active Databases: Two Paradigms or Ends of a Spectrum?

This position paper considers several existing relational database rule languages with a focus on exploring the fundamental differences between deductive and active databases. We find that deductive and active databases do not form two discernible classes, but rather they delineate two ends of a spectrum of database rule languages. We claim that this spectrum also corresponds to a notion of abstraction level, with deductive rule languages at a higher level and active rule languages at a lower level. 1 Introduction Research on incorporating rule processing into database systems historically has been divided into two distinct areas: deductive databases and active databases. In deductive databases, logic programming style rules are used to provide a more powerful user interface than that provided by most database query languages [CGT90, Ull89]. In active databases, production style rules are used to provide automatic execution of database operations in response to certain events and/or c..