Issue No. 01 - January (2012 vol. 24)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TKDE.2010.221
Liang Xu , National University of Singapore, Singapore
Tok Wang Ling , National University of Singapore, Singapore
Huayu Wu , Institute for Infocomm Research, Singapore
Dynamic XML labeling schemes have important applications in XML Database Management Systems. In this paper, we explore dynamic XML labeling schemes from a novel order-centric perspective. We compare the various labeling schemes proposed in the literature with a special focus on their orders of labels. We show that the order of labels fundamentally impacts the update performance of a labeling scheme and develop an order-based framework to classify and characterize XML labeling schemes. Although there are dynamic XML labeling schemes that can completely avoid relabeling, the gain in update performance all come with considerable costs such as larger label size and lower query performance, even if the XML documents are hardly updated. We introduce vector order which is the foundation of the dynamic labeling schemes we propose. Compared with previous solutions that are based on natural order or lexicographical order, vector order is a simple, yet most effective solution to process updates in XML DBMS. We show that vector order can be gracefully applied to both range-based and prefix-based labeling schemes with little overhead introduced. Moreover, vector order-based labeling schemes are not only efficient to process, but also resilient to skewed insertions. Qualitative and experimental evaluations confirm the benefits of our approach compared to previous solutions.
Tree node labeling, XML data management, update processing, query processing.
L. Xu, H. Wu and T. W. Ling, "Labeling Dynamic XML Documents: An Order-Centric Approach," in IEEE Transactions on Knowledge & Data Engineering, vol. 24, no. , pp. 100-113, 2010.