Inproceedings,

The Complexity of Resilience Problems via Valued Constraint Satisfaction Problems

, , and .
Proceedings of the 39th Annual ACM/IEEE Symposium on Logic in Computer Science, page 1–14. New York, NY, USA, Association for Computing Machinery, (Jul 8, 2024)
DOI: 10.1145/3661814.3662071

Abstract

Valued constraint satisfaction problems (VCSPs) constitute a large class of computational optimisation problems. It was shown recently that, over finite domains, every VCSP is in P or NP-complete, depending on the admitted cost functions. In this article, we study cost functions over countably infinite domains whose automorphisms form an oligomorphic permutation group. Our results include a hardness condition based on a generalisation of pp-constructability as known from classical CSPs and a polynomial-time tractability condition based on the concept of fractional polymorphisms. We then observe that the resilience problem for unions of conjunctive queries (UCQs) studied in database theory, under bag semantics, may be viewed as a special case of the VCSPs that we consider. We obtain a complexity dichotomy for the case of incidence-acyclic UCQs and exemplarily use our methods to determine the complexity of a query that had remained open in the literature. Further, we conjecture that our hardness and tractability conditions match for resilience problems for UCQs.

Tags

Users

  • @scadsfct

Comments and Reviews