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: 8250
Venue: VLDB
Year: 1992
Pagerank: 0.00012682631
Overall Rank: 1,012 | 93.06%
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
71	Including Group-By in Query Optimization	1994	VLDB	0.00038021159
290	An Overview of Query Optimization in Relational Systems	1998	PODS	0.0002227038
1,124	Query Optimization by Predicate Move-Around	1994	VLDB	0.00012087356
1,341	Experiences Building the Open OODB Query Optimizer	1993	SIGMOD	0.00011108876
1,362	Execution Strategies for SQL Subqueries	2007	SIGMOD	0.00011032204
1,982	WeTune: Automatic Discovery and Verification of Query Rewrite Rules	2022	SIGMOD	9.3573897e-05
2,095	Enhanced Subquery Optimizations in Oracle	2009	VLDB	9.1803718e-05
3,158	Solving the Join Ordering Problem via Mixed Integer Linear Programming	2017	SIGMOD	7.6888079e-05
3,650	Implementation of Magic-sets in a Relational Database System	1994	SIGMOD	7.2249961e-05
3,769	Proving Query Equivalence Using Linear Integer Arithmetic	2023	SIGMOD	7.1403543e-05
3,779	EROC: A Toolkit for Building NEATO Query Optimizers	1996	VLDB	7.1326925e-05
4,134	Rule Languages and Internal Algebras for Rule-Based Optimizers	1996	SIGMOD	6.8816554e-05
4,363	GenRewrite: Query Rewriting via Large Language Models	2026	SIGMOD	6.7423909e-05
4,576	Efficient Evaluation of XQuery over Streaming Data	2005	VLDB	6.6216442e-05
5,951	Query Unnesting in Object-Oriented Databases	1998	SIGMOD	6.0313489e-05
7,272	SQL Query Optimization: Reordering for a General Class of Queries	1996	SIGMOD	5.6594801e-05
7,787	A Practical Approach to Groupjoin and Nested Aggregates	2021	VLDB	5.5449593e-05
8,164	SlabCity: Whole-Query Optimization using Program Synthesis	2023	VLDB	5.4750309e-05
11,234	Window Function Expression: Let the Self-join Enter	2024	VLDB	5.093636e-05
12,727	A Nested Relational Approach to Processing SQL Subqueries	2005	SIGMOD	5.093636e-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
95	Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates, and Quantifiers	1987	VLDB	0.00034607909
129	Optimization of Nested SQL Queries Revisited	1987	SIGMOD	0.0003068101
325	Implementation Of A Structured English Query Language	1975	SIGMOD	0.00021162719
1,052	Query Graphs, Implementing Trees, and Freely-Reorderable Outerjoins	1990	SIGMOD	0.00012405308
2,815	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB	8.0964463e-05

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2	2,198	A Recursive Algebra and Query Optimization for Nested Relations	1989	SIGMOD
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4	1,887	Extending the Algebraic Framework of Query Processing to Handle Outerjoins	1984	VLDB
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7	95	Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates, and Quantifiers	1987	VLDB
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9	12,727	A Nested Relational Approach to Processing SQL Subqueries	2005	SIGMOD
10	2,815	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB