Query answering in inconsistent Databases

In this chapter, we summarize the research on querying inconsistent databases that we have been conducting during the last five years. The formal framework that we have used is based on two concepts: repair and consistent query answer. We describe different approaches to the issue of computing consistent query answers: query transformation, logic programming, inference in annotated logics, and specialized algorithms. We also characterize the computational complexity of this problem. Finally, we discuss related research in artificial intelligence, databases, and logic programming.