Troubles with Nulls, Views from the Users

Summary: An empirical survey of practitioners shows NULLs are ubiquitous and SQL's null-handling features cause real-world problems. It argues foundational nulls research misdirected, urging theory-practice bridging and a reorientation of data-management work. (summarized by gpt-5-nano on Feb 09 2026)

Paper ID: 12938
Venue: VLDB
Year: 2022
Pagerank: 6.2406439e-05
Overall Rank: 5,378 | 63.11%
DOI: 10.14778/3551793.3551818

Incoming Non-self Citations Over Time

Authors

1. Etienne Toussaint (University of Edinburgh)
2. Paolo Guagliardo (University of Edinburgh)
3. Leonid Libkin (University of Edinburgh; École Normale Supérieure)
4. Juan Sequeda (data.world)

BibTeX Citation

@article{toussaint_vldb22,
        title = {{Troubles with Nulls, Views from the Users}},
        author = {Toussaint, Etienne and Guagliardo, Paolo and Libkin, Leonid and Sequeda, Juan},
        journal = {PVLDB},
        series = {{VLDB} '22},
        volume = {15},
        number = {11},
        pages = {2613--2625},
        doi = {10.14778/3551793.3551818},
        url = {https://doi.org/10.14778/3551793.3551818},
        year = {2022}
}

Incoming Citations (Sorted by Pagerank)

Showing 5 of 5 citing papers.

Rank	Citing Paper	Year	Venue	Pagerank
6,950	SQL Nulls and Two-Valued Logic	2023	PODS	5.7303405e-05
8,407	On The Reasonable Effectiveness of Relational Diagrams: Explaining Relational Query Patterns and the Pattern Expressiveness of Relational Languages	2024	SIGMOD	5.4312823e-05
9,993	In-Database Data Imputation	2024	SIGMOD	5.1815618e-05
10,136	On the Vexing Difficulty of Evaluating IN Predicates	2026	CIDR	5.093636e-05
11,206	Understanding and Reusing Test Suites Across Database Systems	2024	SIGMOD	5.093636e-05

Outgoing Citations (Sorted by Pagerank)

Showing 11 of 11 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
264	The Ubiquity of Large Graphs and Surprising Challenges of Graph Processing	2018	VLDB	0.00022980015
613	Database Relations with Null Values (Extended Abstract)	1982	PODS	0.00015723523
1,690	Incomplete Objects - A Data Model for Design and Planning Applications	1991	SIGMOD	0.00010001011
3,733	Closed World Databases Opened Through Null Values	1988	VLDB	7.1653591e-05
4,032	On Relational Algebra With Marked Nulls	1984	PODS	6.9453392e-05
4,811	Uncertainty Annotated Databases - A Lightweight Approach for Approximating Certain Answers	2019	SIGMOD	6.4983069e-05
5,271	Incomplete Data: What Went Wrong, and How to Fix It	2014	PODS	6.2907571e-05
5,677	Making SQL Queries Correct on Incomplete Databases: A Feasibility Study	2016	PODS	6.1248899e-05
5,943	ACID: A System for Computing Approximate Certain Query Answers over Incomplete Databases	2018	SIGMOD	6.0331149e-05
8,837	Coping with Incomplete Data: Recent Advances	2020	PODS	5.3596619e-05

Semantically Similar Papers

#	Overall Rank	Paper	Year	Venue
1	13,152	A Sound and Complete Query Evaluation Algorithm for Relational Databases with Null Values	1988	SIGMOD
2	5,271	Incomplete Data: What Went Wrong, and How to Fix It	2014	PODS
3	6,627	Schema-free SQL	2014	SIGMOD
4	4,303	Possible and Certain SQL Keys	2015	VLDB
5	3,925	A Formal Semantics of SQL Queries, Its Validation, and Applications	2018	VLDB
6	3,733	Closed World Databases Opened Through Null Values	1988	VLDB
7	6,950	SQL Nulls and Two-Valued Logic	2023	PODS
8	1,380	Null Values in Data Base Management: A Denotational Semantics Approach	1979	SIGMOD
9	5,677	Making SQL Queries Correct on Incomplete Databases: A Feasibility Study	2016	PODS
10	613	Database Relations with Null Values (Extended Abstract)	1982	PODS