Cardinality constraints as well as key dependencies and functional dependencies are among the most popular classes of constraints in database models. While the formal properties of each of the constraint classes are now well understood, little is known about their interaction. The objective of this paper is to discuss how constraints from these classes go together. We propose methods for reasoning about a set of cardinality constraints, key and certain functional dependencies. Moreover, we construct Armstrong databases for these constraints, which are of special interest for example-based deduction in database design.
['Sven Hartmann']
On Interactions of Cardinality Constraints, Key, and Functional Dependencies