An Efficient Encoding and Labeling Based Upon Continued Fraction for Dynamic XML Data

In order to efficiently determine ancestor-descendant relationships between any two random XML nodes and the document-order between the nodes and to avoid re-labeling for updates, much research about labeling schemes has been conducted. In this paper we present a new efficient XML encoding and labeling scheme for dynamic XML document called CFE (Continued Fraction-based Encoding) which labels nodes with continued fractions. CFE has three important properties which form the foundations of this paper: (1) CFE supports that 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) Moreover, CFE supports all structural relationships query in XPath. The experimental results show that CFE provides fairly reasonable XML query processing performance while completely avoiding re-labeling for updates.