Improved Unnesting Algorithms for Join Aggregate SQL Queries

Summary: Presents a modified Kim unnesting algorithm for join-aggregate SQL queries that avoids the COUNT bug while retaining efficiency. Precomputed aggregates and top-down join/outer-join evaluation reduce Cartesian products and broaden applicability. (summarized by gpt-5.6-luna on Jul 24 2026)

Paper ID: h2ac9d5d73c8dfc0d
Venue: VLDB
Year: 1992
Pagerank: 0.00012500439
Overall Rank: 1,015 | 93.18%
DOI: -

Incoming Non-self Citations Over Time

Authors

1. M. Muralikrishna (Digital Equipment Corporation)

BibTeX Citation

@article{muralikrishna_vldb92,
        title = {{Improved Unnesting Algorithms for Join Aggregate SQL Queries}},
        author = {Muralikrishna, M.},
        journal = {PVLDB},
        series = {{VLDB} '92},
        year = {1992}
}

Incoming Citations (Sorted by Pagerank)

Showing 20 of 20 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
73	Including Group-By in Query Optimization	1994	VLDB	0.00037522101
272	An Overview of Query Optimization in Relational Systems	1998	PODS	0.00022509573
1,119	Query Optimization by Predicate Move-Around	1994	VLDB	0.00011950395
1,376	Experiences Building the Open OODB Query Optimizer	1993	SIGMOD	0.00010874518
1,378	Execution Strategies for SQL Subqueries	2007	SIGMOD	0.00010864448
1,893	WeTune: Automatic Discovery and Verification of Query Rewrite Rules	2022	SIGMOD	9.4126198e-05
2,108	Enhanced Subquery Optimizations in Oracle	2009	VLDB	9.0272361e-05
2,961	Proving Query Equivalence Using Linear Integer Arithmetic	2023	SIGMOD	7.8068219e-05
3,139	Solving the Join Ordering Problem via Mixed Integer Linear Programming	2017	SIGMOD	7.6046928e-05
3,336	GenRewrite: Query Rewriting via Large Language Models	2026	SIGMOD	7.4137763e-05
3,707	Implementation of Magic-sets in a Relational Database System	1994	SIGMOD	7.0820673e-05
3,849	EROC: A Toolkit for Building NEATO Query Optimizers	1996	VLDB	6.9810881e-05
4,181	Rule Languages and Internal Algebras for Rule-Based Optimizers	1996	SIGMOD	6.755142e-05
4,677	Efficient Evaluation of XQuery over Streaming Data	2005	VLDB	6.4733736e-05
6,048	Query Unnesting in Object-Oriented Databases	1998	SIGMOD	5.9048465e-05
7,344	SQL Query Optimization: Reordering for a General Class of Queries	1996	SIGMOD	5.5466492e-05
7,907	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.4287568e-05
7,931	SlabCity: Whole-Query Optimization using Program Synthesis	2023	VLDB	5.4238328e-05
9,652	Window Function Expression: Let the Self-join Enter	2024	VLDB	5.1453267e-05
13,017	A Nested Relational Approach to Processing SQL Subqueries	2005	SIGMOD	4.9793485e-05

Outgoing Citations (Sorted by Pagerank)

Showing 5 of 5 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
97	Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates, and Quantifiers	1987	VLDB	0.00034124569
132	Optimization of Nested SQL Queries Revisited	1987	SIGMOD	0.00030241193
333	Implementation Of A Structured English Query Language	1975	SIGMOD	0.00020762482
1,057	Query Graphs, Implementing Trees, and Freely-Reorderable Outerjoins	1990	SIGMOD	0.00012231557
2,864	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB	7.9273714e-05

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10	2,864	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB