Sep 2009 – Feb 2017
Preference SQL is an ongoing research project at the Chair for Databases and Information Systems at the University of Augsburg. It is a Java middleware that connects to any SQL database system and provides a Best-Matches-Only (BMO) search paradigm based on preferences. For this purpose, Standard SQL is extended with a PREFERRING clause to add preferences in the form of strict partial orders as soft constraints.
The system provides a parser, algebraic and cost-based optimizer, and specialized evaluation algorithms. It integrates into any given application, avoids empty results and mitigates flooding. Furthermore, it adds a means of personalization by providing a rich set of tools for user modeling via preference constructors.