Database Querying under Changing Preferences

TL;DR

This paper develops a formal foundation for iterative preference query construction, focusing on query modification through preference relation revision, and analyzes properties and algebraic laws for incremental evaluation.

Contribution

It introduces a formal framework for preference query revision, analyzing order properties and algebraic laws for incremental evaluation in preference-based database querying.

Findings

Analysis of preference relation properties during revision

Formulation of algebraic laws for incremental evaluation

Consideration of finite restrictions and weak-order extensions

Abstract

We present here a formal foundation for an iterative and incremental approach to constructing and evaluating preference queries. Our main focus is on query modification: a query transformation approach which works by revising the preference relation in the query. We provide a detailed analysis of the cases where the order-theoretic properties of the preference relation are preserved by the revision. We consider a number of different revision operators: union, prioritized and Pareto composition. We also formulate algebraic laws that enable incremental evaluation of preference queries. Finally, we consider two variations of the basic framework: finite restrictions of preference relations and weak-order extensions of strict partial order preference relations.