General and Fractional Hypertree Decompositions: Hard and Easy Cases
Summary: Settles the long-standing complexity question: testing fhw(H) ≤ 2 is NP-complete, and via the same construction establishes NP-completeness for ghw(H) ≤ 2. Also identifies structural restrictions yielding tractable bounded-width testing. (summarized by gpt-5.6-luna on Jul 26 2026)
Incoming Non-self Citations Over Time
Authors
- 1. Wolfgang Fischl (Vienna University of Technology)
- 2. Georg Gottlob (University of Oxford; Vienna University of Technology)
- 3. Reinhard Pichler (Vienna University of Technology)
BibTeX Citation
@inproceedings{fischl_pods18,
address = {New York, NY, USA},
series = {{PODS} '18},
title = {{General and Fractional Hypertree Decompositions: Hard and Easy Cases}},
url = {https://dl.acm.org/doi/10.1145/3196959.3196962},
doi = {10.1145/3196959.3196962},
booktitle = {Proceedings of the {ACM} {SIGMOD} Symposium on {Principles} of {Database} {Systems}},
publisher = {Association for Computing Machinery},
author = {Fischl, Wolfgang and Gottlob, Georg and Pichler, Reinhard},
year = {2018}
}
Incoming Citations (Sorted by Pagerank)
Showing 5 of 5 citing papers.
| Rank | Citing Paper | Year | Venue | Pagerank |
|---|---|---|---|---|
| 1,091 | What do Shannon-type Inequalities, Submodular Width, and Disjunctive Datalog have to do with one another? | 2017 | PODS | 0.00012074152 |
| 5,601 | HyperBench: A Benchmark and Tool for Hypergraphs and Empirical Findings | 2019 | PODS | 6.0706976e-05 |
| 10,398 | The Space-Time Complexity of Sum-Product Queries | 2026 | PODS | 4.9793485e-05 |
| 11,656 | A Branch-&-Bound Algorithm for Fractional Hypertree Decomposition | 2024 | VLDB | 4.9793485e-05 |
| 11,735 | Lightweight Materialization for Fast Dashboards Over Joins | 2023 | SIGMOD | 4.9793485e-05 |
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Outgoing Citations (Sorted by Pagerank)
Showing 9 of 9 cited papers.
Citations counted here include only citations to other VLDB/SIGMOD/CIDR/PODS papers in this database.
| Rank | Cited Paper | Year | Venue | Pagerank |
|---|---|---|---|---|
| 208 | EmptyHeaded: A Relational Engine for Graph Processing | 2016 | SIGMOD | 0.00024884544 |
| 357 | FAQ: Questions Asked Frequently | 2016 | PODS | 0.00020020639 |
| 390 | Conjunctive-Query Containment and Constraint Satisfaction | 1998 | PODS | 0.00019248147 |
| 466 | Design and Implementation of the LogicBlox System | 2015 | SIGMOD | 0.00017773029 |
| 540 | An Analytical Study of Large SPARQL Query Logs | 2018 | VLDB | 0.00016726545 |
| 684 | Generalized Hypertree Decompositions: NP-Hardness and Tractable Variants | 2007 | PODS | 0.00014798237 |
| 849 | Aggregation and Ordering in Factorised Databases | 2013 | VLDB | 0.00013504405 |
| 1,812 | Joins via Geometric Resolutions: Worst-case and Beyond | 2015 | PODS | 9.5803973e-05 |
| 3,908 | DunceCap: Query Plans Using Generalized Hypertree Decompositions | 2015 | SIGMOD | 6.9320489e-05 |
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