Parameterised Complexity of Consistent Query Answering via Graph Representations
Abstract
We study consistent query answering via different graph representations. First, we introduce solution-conflict hypergraphs in which nodes represent facts and edges represent either conflicts or query solutions. Considering a monotonic query and a set of antimonotonic constraints, we present an explicit algorithm for counting the number of repairs satisfying the query based on a tree decomposition of the solution-conflict hypergraph. The algorithm not only provides fixed-parameter tractability results for data complexity over expressive query and constraint classes, but also introduces a novel and potentially implementable approach to repair counting. Second, we consider the Gaifman graphs arising from MSO descriptions of consistent query answering. Using a generalization of Courcelle's theorem, we then present fixed-parameter tractability results for combined complexity over expressive query and constraint classes.
Cite
@article{arxiv.2412.08324,
title = {Parameterised Complexity of Consistent Query Answering via Graph Representations},
author = {Teemu Hankala and Miika Hannula and Yasir Mahmood and Arne Meier},
journal= {arXiv preprint arXiv:2412.08324},
year = {2024}
}