Efficient Processing of XML Twig Queries with All Predicates

Abstract

Finding all the occurrences of a twig pattern in an XML database is a core operation for efficient evaluation of XML queries. Some researches have proposed part solutions to process XML twig queries with AND,OR, or NOT predicates. However, very Little work has handled a twig query with three predicates comprehensively. In this paper, we propose a novel path-partitioned encoding scheme, and present a powerful XPattern extended from tree pattern with logic predicates. We also develop a holistic twig join algorithm, called MPTwig, which is designed for efficient matching an XML twig pattern with compound and nested predicates. We show that MPTwig based on path-partitioned encoding scheme guarantee the I/O and CPU optimality. Finally, experimental results on a representative data set indicate that the proposed algorithm performs significantly.