Accelerating Queries with Group-By and Join by Groupjoin

Summary: Introduces groupjoin, a fused operator that merges joins with group-by aggregation to avoid redundant work in aggregation queries. Two correctness-proven equivalences enable this transformation, yielding significant TPC-H speedups. (summarized by gpt-5.6-luna on Jul 24 2026)

Paper ID: 10504
Venue: VLDB
Year: 2011
Pagerank: 6.8224393e-05
Overall Rank: 4,223 | 71.03%
DOI: 10.14778/3402707.3402723

Incoming Non-self Citations Over Time

Authors

1. Guido Moerkotte (University of Mannheim)
2. Thomas Neumann (Technical University of Munich)

BibTeX Citation

@article{moerkotte_vldb11,
        title = {{Accelerating Queries with Group-By and Join by Groupjoin}},
        author = {Moerkotte, Guido and Neumann, Thomas},
        journal = {PVLDB},
        series = {{VLDB} '11},
        volume = {4},
        number = {11},
        pages = {843--854},
        doi = {10.14778/3402707.3402723},
        url = {https://doi.org/10.14778/3402707.3402723},
        year = {2011}
}

Incoming Citations (Sorted by Pagerank)

Showing 16 of 16 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
1,379	Relaxed Operator Fusion for In-Memory Databases: Making Compilation, Vectorization, and Prefetching Work Together At Last	2018	VLDB	0.00010970894
2,962	To Partition, or Not to Partition, That is the Join Question in a Real System	2021	SIGMOD	7.9170451e-05
4,418	On the Correct and Complete Enumeration of the Core Search Space	2013	SIGMOD	6.7137462e-05
6,253	Declarative Sub-Operators for Universal Data Processing	2023	VLDB	5.940599e-05
6,263	Database Technology for the Masses: Sub-Operators as First-Class Entities	2021	VLDB	5.936052e-05
6,538	UPLIFT: Parallelization Strategies for Feature Transformations in Machine Learning Workloads	2022	VLDB	5.8477764e-05
7,160	DAPHNE: An Open and Extensible System Infrastructure for Integrated Data Analysis Pipelines	2022	CIDR	5.6855887e-05
7,721	Identifying Insufficient Data Coverage in Databases with Multiple Relations	2020	VLDB	5.5587371e-05
7,787	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.5449593e-05
8,494	POLAR: Adaptive and Non-invasive Join Order Selection via Plans of Least Resistance	2024	VLDB	5.4142129e-05
9,450	Engineering High-Performance Database Engines	2014	VLDB	5.2660195e-05
10,106	How to Optimize SQL Queries? A Comparison Between Split, Holistic, and Hybrid Approaches	2025	VLDB	5.1435736e-05
10,292	SPALM: A Sparsity-Pattern-Adaptive Library for Matrices	2026	SIGMOD	5.093636e-05
11,234	Window Function Expression: Let the Self-join Enter	2024	VLDB	5.093636e-05
11,297	Grouping, Subsumption, and Disjunctive Join Optimizations in Oracle	2024	VLDB	5.093636e-05
12,057	Index-Assisted Hierarchical Computations in Main-Memory RDBMS	2016	VLDB	5.093636e-05

Outgoing Citations (Sorted by Pagerank)

Showing 6 of 6 cited papers.

Citations counted here include only citations to other VLDB/SIGMOD/CIDR/PODS papers in this database.

Rank	Cited Paper	Year	Venue	Pagerank
206	Eager Aggregation and Lazy Aggregation	1995	VLDB	0.00025092273
210	An Evaluation of Non-Equijoin Algorithms	1991	VLDB	0.00024797689
745	Access Paths in the "Abe" Statistical Query Facility	1982	SIGMOD	0.00014403889
1,013	Dynamic Programming Strikes Back	2008	SIGMOD	0.00012652549
2,095	Enhanced Subquery Optimizations in Oracle	2009	VLDB	9.1803718e-05
7,020	The Generalized Pre-Grouping Transformation: Aggregate Query Optimization in the Presence of Dependencies	2003	VLDB	5.7245921e-05

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