Causes for Query Answers from Databases: Datalog Abduction, View-Updates, and Integrity Constraints

TL;DR

This paper explores the connections between query-answer causality, abductive diagnosis, view updates, and integrity constraints in databases, providing new complexity results and algorithmic insights for causality analysis.

Contribution

It establishes formal links between QA-causality, abductive diagnosis, and view-update problems, advancing understanding and algorithms for causality in databases with integrity constraints.

Findings

New complexity results for QA-causality and view-conditioned causality.

Algorithmic tools derived from abduction for causality analysis.

Connections between causality, diagnosis, and database repairs.

Abstract

Causality has been recently introduced in databases, to model, characterize, and possibly compute causes for query answers. Connections between QA-causality and consistency-based diagnosis and database repairs (wrt. integrity constraint violations) have already been established. In this work we establish precise connections between QA-causality and both abductive diagnosis and the view-update problem in databases, allowing us to obtain new algorithmic and complexity results for QA-causality. We also obtain new results on the complexity of view-conditioned causality, and investigate the notion of QA-causality in the presence of integrity constraints, obtaining complexity results from a connection with view-conditioned causality. The abduction connection under integrity constraints allows us to obtain algorithmic tools for QA-causality.