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: 0.00012495751
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	0.0003750677
272	An Overview of Query Optimization in Relational Systems	1998	PODS	0.0002251422
1,119	Query Optimization by Predicate Move-Around	1994	VLDB	0.00011946162
1,376	Experiences Building the Open OODB Query Optimizer	1993	SIGMOD	0.0001086956
1,378	Execution Strategies for SQL Subqueries	2007	SIGMOD	0.00010859556
1,890	WeTune: Automatic Discovery and Verification of Query Rewrite Rules	2022	SIGMOD	9.4234723e-05
2,109	Enhanced Subquery Optimizations in Oracle	2009	VLDB	9.0230202e-05
2,963	Proving Query Equivalence Using Linear Integer Arithmetic	2023	SIGMOD	7.8035846e-05
3,140	Solving the Join Ordering Problem via Mixed Integer Linear Programming	2017	SIGMOD	7.6012971e-05
3,321	GenRewrite: Query Rewriting via Large Language Models	2026	SIGMOD	7.427185e-05
3,707	Implementation of Magic-sets in a Relational Database System	1994	SIGMOD	7.0789307e-05
3,850	EROC: A Toolkit for Building NEATO Query Optimizers	1996	VLDB	6.9778459e-05
4,180	Rule Languages and Internal Algebras for Rule-Based Optimizers	1996	SIGMOD	6.7524714e-05
4,680	Efficient Evaluation of XQuery over Streaming Data	2005	VLDB	6.4703119e-05
6,050	Query Unnesting in Object-Oriented Databases	1998	SIGMOD	5.9020654e-05
7,347	SQL Query Optimization: Reordering for a General Class of Queries	1996	SIGMOD	5.5440235e-05
7,911	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.4261869e-05
7,929	SlabCity: Whole-Query Optimization using Program Synthesis	2023	VLDB	5.4231855e-05
9,659	Window Function Expression: Let the Self-join Enter	2024	VLDB	5.142891e-05
13,023	A Nested Relational Approach to Processing SQL Subqueries	2005	SIGMOD	4.9769913e-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	0.00034111286
132	Optimization of Nested SQL Queries Revisited	1987	SIGMOD	0.00030228229
333	Implementation Of A Structured English Query Language	1975	SIGMOD	0.00020753575
1,057	Query Graphs, Implementing Trees, and Freely-Reorderable Outerjoins	1990	SIGMOD	0.00012226471
2,865	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB	7.9237122e-05

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10	2,865	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB