文章基本信息

标题：Database Repairing with Soft Functional Dependencies
本地全文：下载
作者：Carmeli, Nofar ; Grohe, Martin ; Kimelfeld, Benny 等
期刊名称：LIPIcs : Leibniz International Proceedings in Informatics
电子版ISSN：1868-8969
出版年度：2021
卷号：186
页码：16:1-16:17
DOI：10.4230/LIPIcs.ICDT.2021.16
出版社：Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
摘要：A common interpretation of soft constraints penalizes the database for every violation of every constraint, where the penalty is the cost (weight) of the constraint. A computational challenge is that of finding an optimal subset: a collection of database tuples that minimizes the total penalty when each tuple has a cost of being excluded. When the constraints are strict (i.e., have an infinite cost), this subset is a "cardinality repair" of an inconsistent database; in soft interpretations, this subset corresponds to a "most probable world" of a probabilistic database, a "most likely intention" of a probabilistic unclean database, and so on. Within the class of functional dependencies, the complexity of finding a cardinality repair is thoroughly understood. Yet, very little is known about the complexity of finding an optimal subset for the more general soft semantics. This paper makes a significant progress in this direction. In addition to general insights about the hardness and approximability of the problem, we present algorithms for two special cases: a single functional dependency, and a bipartite matching. The latter is the problem of finding an optimal "almost matching" of a bipartite graph where a penalty is paid for every lost edge and every violation of monogamy.
关键词：Database inconsistency; database repairs; integrity constraints; soft constraints; functional dependencies