Boosting twig joins in probabilistic XML

Abstract

In practice, uncertainty of data is inherent. Probabilistic XML has been proposed to manage semistructured uncertain data. In this paper, we study twig query evaluation over probabilistic XML with probability thresholds. First we propose an encoding scheme for probabilistic XML. Then we design a novel streaming scheme which enables us to prune off useless inputs. Based on the encoding scheme and streaming scheme, we develop an algorithm to evaluate twig queries over probabilistic XML. Finally, we conduct experiments to study the performance of our algorithm. © 2011 Springer-Verlag Berlin Heidelberg.