Fuzzy functional dependencies and lossless join decomposition of fuzzy relational database systems
ACM Transactions on Database Systems (TODS)
Relational database theory
Approximate inference of functional dependencies from relations
ICDT '92 Selected papers of the fourth international conference on Database theory
A probabilistic relational model and algebra
ACM Transactions on Database Systems (TODS)
ProbView: a flexible probabilistic database system
ACM Transactions on Database Systems (TODS)
Fuzzy functional dependencies and redundancy elimination
Journal of the American Society for Information Science - Special issue: management of imprecision and uncertainty
On the Equivalence of Database Models
Journal of the ACM (JACM)
The Management of Probabilistic Data
IEEE Transactions on Knowledge and Data Engineering
Generalized Normal Forms for Probabilistic Relational Data
IEEE Transactions on Knowledge and Data Engineering
Fuzzy Functional Dependency and Its Application to Approximate Data Querying
IDEAS '00 Proceedings of the 2000 International Symposium on Database Engineering & Applications
Aggregate operators in probabilistic databases
Journal of the ACM (JACM)
BHUNT: automatic discovery of Fuzzy algebraic constraints in relational data
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
Mining hesitation information by vague association rules
ER'07 Proceedings of the 26th international conference on Conceptual modeling
Vague sets or intuitionistic fuzzy sets for handling vague data: which one is better?
ER'05 Proceedings of the 24th international conference on Conceptual Modeling
Maintaining consistency of vague databases using data dependencies
Data & Knowledge Engineering
Mining hesitation information by vague association rules
ER'07 Proceedings of the 26th international conference on Conceptual modeling
Prioritized preferences and choice constraints
ER'07 Proceedings of the 26th international conference on Conceptual modeling
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Vague information is common in many database applications due to internet-scale data dissemination, such as those data arising from sensor networks and mobile communications. We have formalized the notion of a vague relation in order to model vague data in our previous work. In this paper, we utilize Functional Dependencies (FDs), which are the most fundamental integrity constraints that arise in practice in relational databases, to maintain the consistency of a vague relation. The problem we tackle is, given a vague relation r over a schema R and a set of FDs F over R, what is the "best" approximation of r with respect to F when taking into account of the median membership (m) and the imprecision membership (i) thresholds. Using these two thresholds of a vague set, we define the notion of mi-overlap between vague sets and a merge operation on r. Satisfaction of an FD in r is defined in terms of values being mi-overlapping.We show that Lien's and Atzeni's axiom system is sound and complete for FDs being satisfied in vague relations. We study the chase procedure for a vague relation r over R, named VChase(r, F), as a means to maintain consistency of r with respect to F. Our main result is that the output of the procedure is the most object-precise approximation of r with respect to F. The complexity of VChase(r, F) is polynomial time in the sizes of r and F.