Bitmap Filtering: An Efficient Speedup Method for XML Structural Matching

With the proliferation of XML data on the internet, there is a large demand for efficient techniques in XML structural matching. We propose a novel filtering method, which is based on two auxiliary bitmaps named suffix bitmap and prefix bitmap, to accelerate XML structural matching. For each node in the XML document, the suffix bitmap captures in a compact format the tag name list of suffix subtree, and the prefix bitmap captures the tag name list of prefix path respectively. During the structural matching, most of unmatched node candidates can be filtered efficiently by comparing the respective bitmaps. We integrate the bitmap filtering into two categories of structural matching algorithms which are navigation-based algorithms and join-based algorithms. The experimental results demonstrate that the bitmap filtering can improve significantly the performance of XML structural matching.