Efficient query processing for streamed XML fragments

Unlike in traditional databases, queries on XML streams are bounded not only by memory but also by real time processing. Recently proposed Hole-Filler model is promising for information transmission and publication, by slicing XML data into low consuming, easy synchronized fragments. However, XPath queries evaluate the elements in streamed XML data, not the XML fragments, and operation dependence caused by fragments decelerates processing efficiency. By taking advantage of schema information for XML, this paper proposes a model of tid tree to optimize queries over XML fragments by removing "redundant" operations. It then proposes XFPro for processing XPath queries on XML fragments to achieve processing and memory efficiency. Our performance study shows that XFPro performs well both on execution time and memory metrics.