Abstract

Consistent answers from a relational database that violates a given set of integrity constraints are ordinary answers that can be obtained from every repaired version of the database. The database repairs can be specified and interpreted as the stable models of a simple disjunctive normal logic program with database predicates extended with appropriate annotation arguments. The programs can be constructed for any finite set of universal integrity constraints. Programs for referential integrity constraints can also be produced. In consequence, consistent query answers can be obtained from the repair program combined with an appropriate query program under the cautious or skeptical stable model semantics.

Citations