A Database Framework for Probabilistic Preferences

We propose a framework that naturally represents preferences in a probabilistic relational database. The framework augments the relational schema with a special type of a symbol—a preference symbol. Effectively, an instance of a preference symbol can be internally represented as a collection of parametric preference distributions such as Mallows. We establish positive and negative complexity results for evaluating Conjunctive Queries (CQs) over databases where preferences are represented in the Repeated Insertion Model (RIM), Mallows being a special case. This paper is an abbreviated version of our PODS 2017 paper, where an interested reader can find additional details about the formalism and proposed algorithmic solutions.