Disjunctive Databases for Representing Repairs

TL;DR

This paper introduces a method to represent all repairs of an inconsistent database using a canonical disjunctive database, providing a unique and minimal representation for denial constraints.

Contribution

It presents the concept of a canonical disjunctive database for representing repairs and an algorithm to compute it, advancing database repair theory.

Findings

Existence of a unique canonical disjunctive database for repairs.

Algorithm for computing the canonical disjunctive database.

Analysis of the size of the canonical database under functional dependencies.

Abstract

This paper addresses the problem of representing the set of repairs of a possibly inconsistent database by means of a disjunctive database. Specifically, the class of denial constraints is considered. We show that, given a database and a set of denial constraints, there exists a (unique) disjunctive database, called canonical, which represents the repairs of the database w.r.t. the constraints and is contained in any other disjunctive database with the same set of minimal models. We propose an algorithm for computing the canonical disjunctive database. Finally, we study the size of the canonical disjunctive database in the presence of functional dependencies for both repairs and cardinality-based repairs.