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

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