Query rewriting and answering under constraints in data integration systems

Andrea Calì, Domenico Lembo, Riccardo Rosati
2003 International Joint Conference on Artificial Intelligence  
In this paper we address the problem of query answering and rewriting in global-as-view data integration systems, when key and inclusion dependencies are expressed on the global integration schema. In the case of sound views, we provide sound and complete rewriting techniques for a maximal class of constraints for which decidability holds. Then, we introduce a semantics which is able to cope with violations of constraints, and present a sound and complete rewriting technique for the same dec
more » ... ble class of constraints. Finally, we consider the decision problem of query answering and give decidability and complexity results.
dblp:conf/ijcai/CaliLR03 fatcat:hzpf3pw4k5cj7ay74j5dcpjy5i