Querying Inconsistent Databases: Algorithms and Implementation

In this paper, an algorithm for obtaining consistent answers to queries posed to inconsistent relational databases is presented. This is a query rewriting algorithm proven to be sound, terminating and complete for some classes of integrity constraints that extend those previously considered in [1]. Complexity issues are addressed. The implementation of the algorithm in XSB presented here takes advantage of the functionalities of XSB, as a logic programming language with tabling facilities, and the possibility of coupling it to relational database systems.