English

A short note on the counting complexity of conjunctive queries

Logic in Computer Science 2021-12-03 v1 Computational Complexity Databases

Abstract

This note closes a minor gap in the literature on the counting complexity of conjunctive queries by showing that queries that are not free-connex do not have a linear time counting algorithm under standard complexity assumptions. More generally, it is shown that the so-called quantified star size is a lower bound for the exponent in the runtime of any counting algorithm for conjunctive queries.

Keywords

Cite

@article{arxiv.2112.01108,
  title  = {A short note on the counting complexity of conjunctive queries},
  author = {Stefan Mengel},
  journal= {arXiv preprint arXiv:2112.01108},
  year   = {2021}
}
R2 v1 2026-06-24T08:01:13.436Z