Possible and Certain SQL Keys

Summary: Defines possible keys (aligned with SQL UNIQUE) and certain keys (a NULL-tolerant extension of PKs) for identity across NULL-containing relations. Proposes axioms, Armstrong tables, and an indexing scheme to enforce certain keys; experiments show NULLs in real keys and efficient enforcement. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 10991
Venue: VLDB
Year: 2015
Pagerank: 6.1385333e-05
Overall Rank: 4,499 | 68.71%
DOI: -

Incoming Non-self Citations Over Time

Authors

Incoming Citations (Sorted by Pagerank)

Showing 8 of 8 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
2,077	Efficient Discovery of Approximate Dependencies	2018	VLDB	9.6001836e-05
2,574	Discovery of Genuine Functional Dependencies from Relational Data with Missing Values	2018	VLDB	8.5173637e-05
4,127	A Statistical Perspective on Discovering Functional Dependencies in Noisy Data	2020	SIGMOD	6.4310458e-05
7,366	Discovery Algorithms for Embedded Functional Dependencies	2020	SIGMOD	4.7515248e-05
8,085	Discovery and Ranking of Embedded Uniqueness Constraints	2019	VLDB	4.5902231e-05
8,475	DataProf: Semantic Profiling for Iterative Data Cleansing and Business Rule Acquisition	2018	SIGMOD	4.5028904e-05
8,850	Hitting Set Enumeration with Partial Information for Unique Column Combination Discovery	2020	VLDB	4.4364648e-05
11,854	SQL Schema Design: Foundations, Normal Forms, and Normalization	2016	SIGMOD	4.1945683e-05

Outgoing Citations (Sorted by Pagerank)

Showing 13 of 13 cited papers.

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

Rank	Cited Paper	Year	Venue	Pagerank
49	Consistent Query Answers in Inconsistent Databases	1999	PODS	0.00067660624
224	CORDS: Automatic Discovery of Correlations and Soft Functional Dependencies	2004	SIGMOD	0.00032746205
528	Database Relations with Null Values (Extended Abstract)	1982	PODS	0.0002084153
779	Materialized View Maintenance and Integrity Constraint Checking: Trading Space for Time	1996	SIGMOD	0.00016786961
908	Fusing Data with Correlations	2014	SIGMOD	0.00015431241
2,016	Bolt-on Causal Consistency	2013	SIGMOD	9.789465e-05
2,243	The Data Complexity of Consistent Query Answering for Self-Join-Free Conjunctive Queries Under Primary Key Constraints	2015	PODS	9.2166927e-05
2,379	A Revival of Integrity Constraints for Data Cleaning	2008	VLDB	8.9392633e-05
2,549	GORDIAN: Efficient and Scalable Discovery of Composite Keys	2006	VLDB	8.5641554e-05
3,509	Complete Yet Practical Search for Minimal Query Reformulations Under Constraints	2014	SIGMOD	7.0263584e-05
4,640	Transactions And Integrity Constraints	1985	PODS	6.0271345e-05
4,682	Scalable Discovery of Unique Column Combinations	2014	VLDB	6.0022412e-05
8,879	ConsAD: A Real-Time Consistency Anomalies Detector	2012	SIGMOD	4.4301702e-05

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