🤖 AI Summary
This paper investigates inconsistency repair and consistent query answering in databases subject to both general integrity constraints and binary priority relations. We propose a symmetric-difference repair model supporting fact insertion and deletion, and for the first time extend the “optimal repair” semantics to hybrid repair settings involving priorities and arbitrary constraints. We define priority-aware Pareto-optimal repairs and rigorously prove their equivalence to foundation/justified repairs under active integrity constraints. By modeling user preferences via priority relations—and integrating complexity analysis, semantic characterization of repairs, and constraint translation techniques—we systematically establish the data complexity of repair checking and inconsistency-tolerant querying (e.g., coNP-completeness) and provide a formal foundation for repair verification. Our core contribution is a unified framework that integrates priority semantics with classical repair paradigms, enabling interpretable and verifiable preference-aware data repair.
📝 Abstract
This paper revisits the problem of repairing and querying inconsistent databases equipped with universal constraints. We adopt symmetric difference repairs, in which both deletions and additions of facts can be used to restore consistency, and suppose that preferred repair actions are specified via a binary priority relation over (negated) facts. Our first contribution is to show how existing notions of optimal repairs, defined for simpler denial constraints and repairs solely based on fact deletion, can be suitably extended to our richer setting. We next study the computational properties of the resulting repair notions, in particular, the data complexity of repair checking and inconsistency-tolerant query answering. Finally, we clarify the relationship between optimal repairs of prioritized databases and repair notions introduced in the framework of active integrity constraints. In particular, we show that Pareto-optimal repairs in our setting correspond to founded, grounded and justified repairs w.r.t. the active integrity constraints obtained by translating the prioritized database. Our study also yields useful insights into the behavior of active integrity constraints.
