This paper describes the implementation of active rules in the Chimera
object-oriented database system. The Chimera active rule language is
very rich, since it provides alternative semantics for active rules an
d combines several innovative features. We show how a run-time support
for that active rule language is designed and implemented through the
necessary data structures, functional components and algorithms. The
paper also compares Chimera active rule implementation with other acti
ve database system implementations.