In this talk, we briefly introduce two major research problems involving databases and functional dependencies. First, we introduce an information-theoretic measure that evaluates a database design based on the worst possible redundancy carried in the instances. Then we propose new design guidelines to reduce the amount of redundancy that databases carry due to the presence of functional dependencies.
We also introduce the problem of repairing an inconsistent database that violates a set of functional dependencies by making the smallest possible value modifications. We show that finding an optimum solution is NP-hard. Then we explore the possibility of producing an approximate solution that can be used in data cleaning systems.