Optimizing Computation of Repairs from Active Integrity Constraints

Abstract

Active integrity constraints (AICs) are a form of integrity constraints for databases that not only identify inconsistencies, but also suggest how these can be overcome. The semantics for AICs defines different types of repairs, but deciding whether an inconsistent database can be repaired is a NP-or Σ 2 p-complete problem, depending on the type of repairs one has in mind. In this paper, we introduce two different relations on AICs: an equivalence relation of independence, allowing the search to be parallelized among the equivalence classes, and a precedence relation, inducing a stratification that allows repairs to be built progressively. Although these relations have no impact on the worst-case scenario, they can make significant difference in the practical computation of repairs for inconsistent databases.

repAIrC: A Tool for Ensuring Data Consistency - By Means of Active Integrity Constraints

“…We presented a working prototype of a tool, called repAIrC, to check integrity of real-world SQL databases with respect to a given set of active integrity constraints, and to compute different types of repairs automatically in case inconsistency is detected, following the ideas and algorithms in (Flesca et al, 2004;Caroprese et al, 2007;Caroprese and Truszczyński, 2011;Cruz-Filipe et al, 2013;Cruz-Filipe, 2014). This tool is the first implementation of a concept we believe to have the potential to be integrated in current database management systems.…”

“…In particular, the framework of active integrity constraints (Flesca et al, 2004;Caroprese and Truszczyński, 2011) was introduced more recently with the goal of giving operational mechanisms to compute repairs of inconsistent databases. This framework has subsequently been extended to consider preferences (Caroprese et al, 2007) and to find "best" repairs automatically (Cruz-Filipe et al, 2013) and efficiently (Cruz-Filipe, 2014).…”

Integrity Constraints for General-Purpose Knowledge Bases

“…Consequently, there is no need to use MCSs for distributed databases, but this mapping shows that our notion of integrity constraints abstracts the practice in this field. Furthermore, results in previous work [11] indicate that the processing of integrity constraints can be efficiently parallelized in this disjoint scenario, given suitable assumptions.…”

Semantics for Active Integrity Constraints Using Approximation Fixpoint Theory

“…As shown by Cruz-Filipe et al [2013], the semantics of founded repairs [Caroprese et al, 2006] unexpectedly fails to respect the common-sense law of inertia, while the more restricted semantics of justified repairs [Caroprese and Truszczyński, 2011] forbids natural repairs. That work proposed the operational semantics of wellfounded repairs, which however is not modular [Cruz-Filipe, 2014] and therefore restricted in its practical applicability.…”