Global Hash Tables Strike Back! An Analysis of Parallel GROUP BY Aggregation

Summary: Shows a purpose-built fully-concurrent shared hash table for GROUP BY in morsel-driven systems can match or outperform partitioned aggregation across key cardinality, skew, and thread counts. Analyzes resizing/memory-pressure trade-offs and offers implementer guidelines. (summarized by gpt-5-mini on Mar 13 2026)

Paper ID: h36d86fe173a59dc5
Venue: VLDB
Year: 2026
Pagerank: 5.1571823e-05
Overall Rank: 9,561 | 35.72%
DOI: 10.14778/3778092.3778110

Incoming Non-self Citations Over Time

Authors

1. Daniel Xue (University of Pennsylvania)
2. Ryan Marcus (University of Pennsylvania)

BibTeX Citation

@article{xue_vldb26,
        title = {{Global Hash Tables Strike Back! An Analysis of Parallel GROUP BY Aggregation}},
        author = {Xue, Daniel and Marcus, Ryan},
        journal = {PVLDB},
        series = {{VLDB} '26},
        volume = {19},
        number = {3},
        pages = {523--535},
        doi = {10.14778/3778092.3778110},
        url = {https://doi.org/10.14778/3778092.3778110},
        year = {2026}
}

Incoming Citations (Sorted by Pagerank)

Showing 1 of 1 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
10,942	One Ring to Shuffle Them All: Scalable Intra-Process Data Redistribution with Ring-Buffer Shuffle in Redpanda Oxla	2026	VLDB	4.9793485e-05

Outgoing Citations (Sorted by Pagerank)

Showing 14 of 14 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
14	MonetDB/X100: Hyper-Pipelining Query Execution	2005	CIDR	0.00064031282
71	DuckDB: an Embeddable Analytical Database	2019	SIGMOD	0.00037720227
163	DB2 with BLU Acceleration: So Much More than Just a Column Store	2013	VLDB	0.0002749118
179	The Vertica Analytic Database: C-Store 7 Years Later	2012	VLDB	0.00026611886
215	Morsel-Driven Parallelism: A NUMA-Aware Query Evaluation Framework for the Many-Core Age	2014	SIGMOD	0.00024598661
479	The Making of TPC-DS	2006	VLDB	0.00017622471
605	Everything You Always Wanted to Know About Compiled and Vectorized Queries But Were Afraid to Ask	2018	VLDB	0.00015647561
626	Adaptive Aggregation on Chip Multiprocessors	2007	VLDB	0.00015473276
2,245	Cache-Efficient Aggregation: Hashing Is Sorting	2015	SIGMOD	8.7649358e-05
2,818	To Partition, or Not to Partition, That is the Join Question in a Real System	2021	SIGMOD	7.9739791e-05
6,648	Workload Insights From The Snowflake Data Cloud: What Do Production Analytic Queries Really Look Like?	2025	VLDB	5.7215989e-05
7,416	Is Perfect Hashing Practical for OLAP Systems?	2024	CIDR	5.5331654e-05
7,760	IcebergHT: High Performance Hash Tables Through Stability and Low Associativity	2023	SIGMOD	5.457277e-05
7,907	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.4287568e-05

Semantically Similar Papers

#	Overall Rank	Paper	Year	Venue
1	210	Sort vs. Hash Revisited: Fast Join Implementation on Modern Multi-Core CPUs	2009	VLDB
2	5,582	Efficient Computation of Multiple Group By Queries	2005	SIGMOD
3	2,245	Cache-Efficient Aggregation: Hashing Is Sorting	2015	SIGMOD
4	4,754	Performance Analysis of a Load Balancing Hash-Join Algorithm for a Shared Memory Multiprocessor	1991	VLDB
5	3,059	Design and Evaluation of Parallel Pipelined Join Algorithms	1987	SIGMOD
6	6,151	Efficiently Processing Joins and Grouped Aggregations on GPUs	2025	SIGMOD
7	361	Design and Evaluation of Main Memory Hash Join Algorithms for Multi-core CPUs	2011	SIGMOD
8	7,907	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB
9	1,628	Adaptive Parallel Aggregation Algorithms	1995	SIGMOD
10	5,530	Generalized Hash Teams for Join and Group-by	1999	VLDB