Event Condition Action Rules on RDF Metadata in P P Environments

RDF is one of the technologies proposed to realise the vision of the Semantic Web and it is being increasingly used in distributed web based applications The use of RDF in applications that require timely noti cation of metadata changes raises the need for mechanisms for monitoring and processing such changes Event Condition Action ECA rules are a natural candidate to ful ll this need In this paper we study ECA rules on RDF metadata in P P environments We describe a language for de ning ECA rules on RDF metadata including its syntax and execution semantics We develop conservative tests for determining the termination and con uence of sets of such ECA rules We describe an architecture supporting such rules in P P environments and our current implementation of this architecture We also discuss techniques for relaxing the isolation and atomicity requirements of transactions