An Encoding and Labeling Scheme Based on Continued Fraction for Dynamic XML

Much research about labeling schemes has been conducted to efficiently determine the ancestor-descendant relationships and the document-order between any two random XML nodes without re-labeling for updates. In this paper, we present an efficient XML encoding and labeling scheme for dynamic XML document, named Continued Fraction-based Encoding (CFE). The proposed CFE scheme labels nodes with continued fractions and has the following three important properties: (1) CFE codes can be inserted between any two consecutive CFE codes with the orders kept and without re-encoding the existing nodes; (2) CFE is orthogonal to specific labeling schemes, thus it can be applied broadly to different labeling schemes or other applications to efficiently process the updates; (3) CFE supports all structural relationships query in XPath. Two test data sets were built for evaluation. The experimental results show that CFE provides fairly reasonable XML query processing performance while completely avoiding relabeling for updates.