Outerjoins as Disjunctions

Summary: Outerjoins treated as disjunctions rather than preserved joins; yields commutative, associative semantics and aids query rewriting and plan generation. DNF-based analysis reveals data-merging queries that cannot be evaluated by binary outerjoins; proposes alternative evaluation procedures and semijoin-based strategies to reduce base relations. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 2801
Venue: SIGMOD
Year: 1994
Pagerank: 0.00011809075
Overall Rank: 1,176 | 91.94%
DOI: 10.1145/191839.191908

Incoming Non-self Citations Over Time

Authors

1. César A. Galindo-Legaria (Centrum Wiskunde & Informatica)

BibTeX Citation

@inproceedings{galindolegaria_sigmod94,
        title = {{Outerjoins as Disjunctions}},
        author = {Galindo-Legaria, César A.},
        series = {{SIGMOD} '94},
        booktitle = {Proceedings of the {ACM} {SIGMOD} International Conference on Management of Data},
        publisher = {Association for Computing Machinery},
        doi = {10.1145/191839.191908},
        url = {https://dl.acm.org/doi/10.1145/191839.191908},
        year = {1994}
}

Incoming Citations (Sorted by Pagerank)

Showing 16 of 16 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
1,783	Data Fusion – Resolving Data Conflicts for Integration	2009	VLDB	9.772895e-05
2,791	Integrating Information by Outerjoins and Full Disjunctions (Extended Abstract)	1996	PODS	8.119781e-05
3,075	Matching Twigs in Probabilistic XML	2007	VLDB	7.7839831e-05
3,263	Hypergraph based reorderings of outer join queries with complex predicates	1995	SIGMOD	7.584572e-05
3,625	Canonical Abstraction for Outerjoin Optimization	2004	SIGMOD	7.2458252e-05
4,123	Integrating Data Lake Tables	2023	VLDB	6.8878137e-05
4,187	Maximally Joining Probabilistic Data	2007	PODS	6.8456588e-05
4,495	Queries with Incomplete Answers over Semistructured Data	1999	PODS	6.6623097e-05
6,104	MapMerge: Correlating Independent Schema Mappings	2010	VLDB	5.9754714e-05
6,256	View Matching for Outer-Join Views	2005	VLDB	5.9398047e-05
6,373	Full Disjunctions: Polynomial-Delay Iterators in Action	2006	VLDB	5.8946564e-05
7,272	SQL Query Optimization: Reordering for a General Class of Queries	1996	SIGMOD	5.6594801e-05
8,071	An Incremental Algorithm for Computing Ranked Full Disjunctions	2005	PODS	5.4935818e-05
8,098	Designing a Query Language for RDF: Marrying Open and Closed Worlds	2016	PODS	5.4874656e-05
9,646	Computing Full Disjunctions	2003	PODS	5.243371e-05
12,119	Left Bit Right: For SPARQL Join Queries with OPTIONAL Patterns (Left-outer-joins)	2015	SIGMOD	5.093636e-05

Outgoing Citations (Sorted by Pagerank)

Showing 9 of 9 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
10	Extending the Data Base Relational Model to Capture More Meaning	1979	SIGMOD	0.0007727299
15	The Functional Data Model and the Data Language DAPLEX	1979	SIGMOD	0.00061144858
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
182	Federated Database Systems for Managing Distributed, Heterogeneous, and Autonomous Databases	1991	VLDB	0.00026367971
1,052	Query Graphs, Implementing Trees, and Freely-Reorderable Outerjoins	1990	SIGMOD	0.00012405308
1,887	Extending the Algebraic Framework of Query Processing to Handle Outerjoins	1984	VLDB	9.5347906e-05
2,067	A Polygen Model for Heterogeneous Database Systems: The Source Tagging Perspective	1990	VLDB	9.23317e-05
2,815	Optimization and Dataflow Algorithms for Nested Tree Queries	1989	VLDB	8.0964463e-05

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