2026-07-23T15:20:47Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:13724 2024-03-06T10:52:32Z ddc:004 open_access

Database Repairing with Soft Functional Dependencies Carmeli, Nofar Grohe, Martin Kimelfeld, Benny Livshits, Ester Tibi, Muhammad Database inconsistency database repairs integrity constraints soft constraints functional dependencies 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. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Nofar Carmeli and Martin Grohe and Benny Kimelfeld and Ester Livshits and Muhammad Tibi 2021 Is Part Of LIPIcs, Volume 186, 24th International Conference on Database Theory (ICDT 2021) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.ICDT.2021.16 urn:nbn:de:0030-drops-137245 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2021.16 eng https://creativecommons.org/licenses/by/4.0/legalcode