Andrea Calì, Domenico Lembo, Riccardo Rosati.
In Proceedings of the Twentysecond ACM SIGACT SIGMOD SIGART Symposium on Principles of Database Systems (PODS 2003), pages 260-271, ACM Press, 2003. ISBN 1-58113-670-6.
In databases with integrity constraints, data may not satisfy the constraints. In this paper, we address the problem of obtaining consistent answers in such a setting, when key and inclusion dependencies are expressed on the database schema. We establish decidability and complexity results for query answering under different assumptions on data (soundness and/or completeness). In particular, after showing that the problem is in general undecidable, we identify the maximal class of inclusion dependencies under which query answering is decidable in the presence of key dependencies. Although obtained in a single database context, such results are directly applicable to data integration, where multiple information sources may provide data that are inconsistent with respect to the global view of the sources.
@String{PODS-03 = "Proceedings of the Twentysecond ACM SIGACT SIGMOD SIGART Symposium on Principles of Database Systems (PODS~2003)"}
@String{ACM = "{ACM} Press"}
@Inproceedings{CaLR03,
author = "Andrea Cal\`{\i} and Domenico Lembo and Riccardo Rosati",
title = "On the decidability and complexity of query answering over inconsistent and incomplete databases",
booktitle = PODS-03,
pages = "260--271",
publisher = ACM,
year = 2003,
isbn = "1-58113-670-6",
}