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: 10992
Venue: VLDB
Year: 2015
Pagerank: 6.1322784e-05
Overall Rank: 4,502 | 68.72%
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
2,082	Efficient Discovery of Approximate Dependencies	2018	VLDB	9.5875364e-05
2,576	Discovery of Genuine Functional Dependencies from Relational Data with Missing Values	2018	VLDB	8.509121e-05
4,129	A Statistical Perspective on Discovering Functional Dependencies in Noisy Data	2020	SIGMOD	6.4208557e-05
7,361	Discovery Algorithms for Embedded Functional Dependencies	2020	SIGMOD	4.7469673e-05
8,087	Discovery and Ranking of Embedded Uniqueness Constraints	2019	VLDB	4.5858215e-05
8,472	DataProf: Semantic Profiling for Iterative Data Cleansing and Business Rule Acquisition	2018	SIGMOD	4.4985733e-05
8,851	Hitting Set Enumeration with Partial Information for Unique Column Combination Discovery	2020	VLDB	4.4322123e-05
11,862	SQL Schema Design: Foundations, Normal Forms, and Normalization	2016	SIGMOD	4.1905499e-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	0.00067607389
224	CORDS: Automatic Discovery of Correlations and Soft Functional Dependencies	2004	SIGMOD	0.00032743209
529	Database Relations with Null Values (Extended Abstract)	1982	PODS	0.00020825533
775	Materialized View Maintenance and Integrity Constraint Checking: Trading Space for Time	1996	SIGMOD	0.00016775051
906	Fusing Data with Correlations	2014	SIGMOD	0.00015420344
2,008	Bolt-on Causal Consistency	2013	SIGMOD	9.8120677e-05
2,246	The Data Complexity of Consistent Query Answering for Self-Join-Free Conjunctive Queries Under Primary Key Constraints	2015	PODS	9.2039096e-05
2,379	A Revival of Integrity Constraints for Data Cleaning	2008	VLDB	8.9331083e-05
2,551	GORDIAN: Efficient and Scalable Discovery of Composite Keys	2006	VLDB	8.5553153e-05
3,514	Complete Yet Practical Search for Minimal Query Reformulations Under Constraints	2014	SIGMOD	7.0192177e-05
4,643	Transactions And Integrity Constraints	1985	PODS	6.0213009e-05
4,680	Scalable Discovery of Unique Column Combinations	2014	VLDB	5.9964535e-05
8,878	ConsAD: A Real-Time Consistency Anomalies Detector	2012	SIGMOD	4.4259055e-05

Semantically Similar Papers

Overall Rank	Paper	Year	Venue	Pagerank
3,582	Closed World Databases Opened Through Null Values	1988	VLDB	6.9455143e-05
6,781	SQL Nulls and Two-Valued Logic	2023	PODS	4.9227317e-05
6,711	Schema-free SQL	2014	SIGMOD	4.9485222e-05
12,227	When Data Dependencies over SQL Tables Meet the Logics of Paradox and S-3	2010	PODS	4.1905499e-05
7,391	Incomplete Information and Certain Answers in General Data Models	2011	PODS	4.7383385e-05
4,757	On Relational Algebra With Marked Nulls	1984	PODS	5.9358967e-05
5,710	Conjunctive Query Equivalence of Keyed Relational Schemas (Extended Abstract)	1997	PODS	5.3619696e-05
5,393	Troubles with Nulls, Views from the Users	2022	VLDB	5.5319929e-05
2,246	The Data Complexity of Consistent Query Answering for Self-Join-Free Conjunctive Queries Under Primary Key Constraints	2015	PODS	9.2039096e-05
4,150	A Formal Semantics of SQL Queries, Its Validation, and Applications	2018	VLDB	6.4022639e-05