Gesellschaft für Informatik e.V.

Lecture Notes in Informatics


Datenbanksysteme in Business, Technologie und Web (BTW 2007) P-103, 64-81 (2007).


2007


Editors

Alfons Kemper (ed.), Harald Schöning (ed.), Thomas Rose (ed.), Matthias Jarke (ed.), Thomas Seidl (ed.), Christoph Quix (ed.), Christoph Brochhaus (ed.)


Contents

Getting prime cuts from skylines over partially ordered domains

Wolf-Tilo Balke , Wolf Siberski and Ulrich Güntzer

Abstract


Skyline queries have recently received a lot of attention due to their intuitive query formulation: users can state preferences with respect to several attributes. Unlike numerical preferences, preferences over discrete value domains do not show an inherent total order, but have to rely on partial orders as stated by the user. In such orders typically many object values are incomparable, increasing the size of skyline sets significantly, and making their computation expensive. In this paper we explore how to enable interactive tasks like query refinement or relevance feedback by providing `prime cuts'. Prime cuts are interesting subsets of the full Pareto skyline, which give users a good overview over the skyline. They have to be small, efficient to compute, suitable for higher numbers of query predicates, and representative. The key to improved performance and reduced result set sizes is the relaxation of Pareto semantics to the concept of weak Pareto dominance. We argue that this relaxation yields intuitive results and show how it opens up the use of efficient and scalable query processing algorithms. Assessing the practical impact, our experiments show that our approach leads to lean result set sizes and outperforms Pareto skyline computations by up to two orders of magnitude.


Full Text: PDF

ISBN 978-3-88579-197-3


Last changed 04.10.2013 18:13:27