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.

翻译：本文重新审视了配备通用约束的不一致数据库的修复与查询问题。我们采用对称差修复方法，其中可通过事实的删除与添加来恢复一致性，并假设优先修复操作通过（否定）事实间的二元优先关系来指定。我们的首要贡献在于展示了如何将针对更简单的否定约束且仅基于事实删除的最优修复概念，恰当地扩展至当前更丰富的设定中。接下来，我们研究了所得修复概念的计算性质，特别是修复检查和不一致容忍查询应答的数据复杂性。最后，我们阐明了优先数据库的最优修复与主动完整性约束框架中引入的修复概念之间的关系。具体而言，我们证明了在当前设定下的帕累托最优修复，对应于通过转换优先数据库所获得的主动完整性约束下的有基础、有根据且合理的修复。我们的研究也为理解主动完整性约束的行为提供了有益的见解。