DAHC-tree: An Effective Index for Approximate Search in High-Dimensional Metric Spaces
Jurandy Almeida, Eduardo Alves do Valle Junior, Ricardo da Silva Torres, Neucimar J. Leite · Cadernos de Linguística e Teoria da Literatura (Universidade Federal de Minas Gerais) · 2010
Although many algorithms have been proposed for evaluating XPath queries containing child and descendant axes and predicates (XP AT H /,//,[ ] ) against XML data, there are very few efforts towards developing algorithms for processing path expressions with other axes namely, following, preceding, following-sibling and preceding-sibling.In this article, we demonstrate that the conventional twig-structure, which is used to represent expressions in the subset XP AT H /,//,[ ] , has no order information built into it and hence fails to model XPath expressions with ordered axes.This motivates us to introduce a new type of twig-structure, which we call Order-aware Twig, to effectively represent XPath expressions with ordered axes.