A Nested Relational Approach to Processing SQL Subqueries

Summary: Introduces a nested relational approach (nested relational algebra) to process non-aggregate SQL subqueries by directly unnesting them with hash joins, enabling uniform handling of arbitrary nesting. Empirical results show superior performance over rewrite-based methods and discuss algebraic optimization and integration into a relational DBMS. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 3697
Venue: SIGMOD
Year: 2005
Pagerank: 5.093636e-05
Overall Rank: 12,727 | 12.69%
DOI: 10.1145/1066157.1066180

Incoming Non-self Citations Over Time

No non-self incoming citations found for this paper in this database.

Authors

1. Bin Cao (University of Louisville)
2. Antonio Badia (University of Louisville)

BibTeX Citation

@inproceedings{cao_sigmod05,
        title = {{A Nested Relational Approach to Processing SQL Subqueries}},
        author = {Cao, Bin and Badia, Antonio},
        series = {{SIGMOD} '05},
        booktitle = {Proceedings of the {ACM} {SIGMOD} International Conference on Management of Data},
        publisher = {Association for Computing Machinery},
        doi = {10.1145/1066157.1066180},
        url = {https://dl.acm.org/doi/10.1145/1066157.1066180},
        year = {2005}
}

Incoming Citations (Sorted by Pagerank)

Showing 1 of 1 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
12,289	Efficient Implementation of Generalized Quantification in Relational Query Languages	2013	VLDB	5.093636e-05

Outgoing Citations (Sorted by Pagerank)

Showing 8 of 8 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
198	Aggregate-Query Processing in Data Warehousing Environments	1995	VLDB	0.00025618616
543	Orthogonal Optimization of Subqueries and Aggregation	2001	SIGMOD	0.0001682612
1,012	Improved Unnesting Algorithms for Join Aggregate SQL Queries	1992	VLDB	0.00012682631
1,037	Cost-Based Optimization for Magic: Algebra and Implementation	1996	SIGMOD	0.00012494928
1,592	Efficient Processing of Joins on Set-valued Attributes	2003	SIGMOD	0.00010253457
2,815	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB	8.0964463e-05

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8	95	Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates, and Quantifiers	1987	VLDB
9	2,198	A Recursive Algebra and Query Optimization for Nested Relations	1989	SIGMOD
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