Title
Coping with Incomplete Data: Recent Advances
Abstract
Handling incomplete data in a correct manner is a notoriously hard problem in databases. Theoretical approaches rely on the computationally hard notion of certain answers, while practical solutions rely on ad hoc query evaluation techniques based on three-valued logic. Can we find a middle ground, and produce correct answers efficiently? The paper surveys results of the last few years motivated by this question. We re-examine the notion of certainty itself, and show that it is much more varied than previously thought. We identify cases when certain answers can be computed efficiently and, short of that, provide deterministic and probabilistic approximation schemes for them. We look at the role of three-valued logic as used in SQL query evaluation, and discuss the correctness of the choice, as well as the necessity of such a logic for producing query answers.
Year
DOI
Venue
2020
10.1145/3375395.3387970
SIGMOD/PODS '20: International Conference on Management of Data Portland OR USA June, 2020
Keywords
DocType
ISBN
relational databases, incomplete information, certain answers, naive evaluation, approximate query answering, many-valued logics
Conference
978-1-4503-7108-7
Citations 
PageRank 
References 
1
0.35
0
Authors
4
Name
Order
Citations
PageRank
Marco Console16211.71
Paolo Guagliardo210.35
Leonid Libkin33446764.02
Etienne Toussaint411.36