Title: Querying Inconsistent Databases
Authors: S.Greco, E. Zumpano

Abstract:


In this paper we consider the problem of answering queries
consistently in the presence of inconsistent data, i.e. data
violating integrity constraints.
We propose a technique based on the rewriting of integrity
constraints into disjunctive rules with two different forms of
negation (negation as failure and classical negation).
The disjunctive program can be used i)  to generate `repairs'
for the database and ii) to produce consistent answers, i.e. maximal
set of atoms which do not violate the constraints.
We show that our technique is sound, complete and more general
than techniques previously proposed.