Twig Pattern Matching: A Revisit

Twig pattern matching plays a crucial role in xml query processing. In order to reduce the processing time, some existing holistic onephase twig pattern matching algorithms (e.g., HolisticTwigStack [3], TwigFast [5], etc) use the core function getNext of TwigStack [2] to effectively and efficiently filter out the useless elements. However, using getNext as a filter may incur other redundant computation. We propose two approaches, namely re-test checking and forward-to-end, which can avoid the redundant computation and can be easily applied to both holistic one-phase and two-phase algorithms. The experiments show that our approach can significantly improve the efficiency by avoiding the redundant computation.