Efficient Processing of XML Path Queries Using BI Index
Xiang Yu Hu, Yun Yin Mo, Hai Wei Zhang, Xiao Jie Yuan · Applied Mechanics and Materials · 2011
XML has been widely used for information exchange and storage as the de facto data representation format nowadays. Several XML query languages such XPath, XQuery and XML-QL have been proposed. Many structural join algorithms have been proposed for processing XPath queries, Although holistic twig join algorithms has been proved to be I/O optimal in terms of input and output sizes for queries with only ancestor-descendant edges, it cannot control the size of intermediate results for queries with parent-child edges. We address the problem of efficient path queries with mixed of ancestor-descendant and parent-child edges on a simple but novel index, called BI (i.e. Binary Index) based on Dewey labeling scheme. And we propose a new holistic path join algorithm, namely PSBI, which has the same performance as PathStack for query path with only ancestor-descendant edges, but it is significantly more efficient than PathStack for queries with the presence of parent-child edges. Experimental results demonstrate that the PSBI and BI index has a substantial performance improvement compared to original PathStack algorithm.