Restoring consistency in P2P deductive databases

This paper proposes a logic framework for modeling the interaction among deductive databases and computing consistent answers to logic queries in a P2P environment. As usual, data are exchanged among peers by using logical rules, called mapping rules. The declarative semantics of a P2P system is defined in terms of weak models. Under this semantics each peer uses its mapping rules to import minimal sets of mapping atoms allowing to satisfy its local integrity constraints. An equivalent and alternative characterization of minimal weak model semantics, in terms of prioritized logic programs, is also introduced and the computational complexity of P2P logic queries is investigated. © 2012 Springer-Verlag.