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: h1059a0570f992480
Venue: VLDB
Year: 2011
Pagerank: 6.7339503e-05
Overall Rank: 4,209 | 71.71%
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 17 of 17 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
1,341	Relaxed Operator Fusion for In-Memory Databases: Making Compilation, Vectorization, and Prefetching Work Together At Last	2018	VLDB	0.00010968512
2,818	To Partition, or Not to Partition, That is the Join Question in a Real System	2021	SIGMOD	7.9739791e-05
4,464	On the Correct and Complete Enumeration of the Core Search Space	2013	SIGMOD	6.5877622e-05
5,771	Database Technology for the Masses: Sub-Operators as First-Class Entities	2021	VLDB	5.9992698e-05
6,296	Declarative Sub-Operators for Universal Data Processing	2023	VLDB	5.8195258e-05
6,662	UPLIFT: Parallelization Strategies for Feature Transformations in Machine Learning Workloads	2022	VLDB	5.7171651e-05
6,878	DAPHNE: An Open and Extensible System Infrastructure for Integrated Data Analysis Pipelines	2022	CIDR	5.657878e-05
7,410	POLAR: Adaptive and Non-invasive Join Order Selection via Plans of Least Resistance	2024	VLDB	5.5342768e-05
7,880	Identifying Insufficient Data Coverage in Databases with Multiple Relations	2020	VLDB	5.43413e-05
7,907	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.4287568e-05
9,553	Engineering High-Performance Database Engines	2014	VLDB	5.1585591e-05
9,652	Window Function Expression: Let the Self-join Enter	2024	VLDB	5.1453267e-05
10,140	How to Optimize SQL Queries? A Comparison Between Split, Holistic, and Hybrid Approaches	2025	VLDB	5.0742707e-05
10,504	SPALM: A Sparsity-Pattern-Adaptive Library for Matrices	2026	SIGMOD	4.9793485e-05
10,832	ReSequel: Robust LLM-assisted Query Rewriting and Optimization using Templatization and Sampling	2026	VLDB	4.9793485e-05
11,617	Grouping, Subsumption, and Disjunctive Join Optimizations in Oracle	2024	VLDB	4.9793485e-05
12,351	Index-Assisted Hierarchical Computations in Main-Memory RDBMS	2016	VLDB	4.9793485e-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
213	Eager Aggregation and Lazy Aggregation	1995	VLDB	0.00024759805
220	An Evaluation of Non-Equijoin Algorithms	1991	VLDB	0.00024344086
764	Access Paths in the "Abe" Statistical Query Facility	1982	SIGMOD	0.00014127114
884	Dynamic Programming Strikes Back	2008	SIGMOD	0.00013267935
2,108	Enhanced Subquery Optimizations in Oracle	2009	VLDB	9.0272361e-05
7,138	The Generalized Pre-Grouping Transformation: Aggregate Query Optimization in the Presence of Dependencies	2003	VLDB	5.6008068e-05

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