One Practical Range-Based Numbering Scheme for XML Document

It takes constant time to determine the ancestor relation between two nodes in an XML document when the document is indexed with range-based labeling scheme. This constant time procedure makes range-based labeling scheme very attractive. However, relabeling is unavoidable when arbitrary insertions are allowed, and relabeling can be very time-consuming. Relabeling problem limits the use of range-based labeling scheme in naive XML database management system, and document processing systems where insertions and deletions are frequent. In this paper, we present one practical algorithm to extend range labeling scheme (extended preorder) for indexing XML documents. Under this new scheme, arbitrary insertions can be accommodated without relabeling. The new method can be viewed as a combination of rangebased labeling and prefix-based labeling. Range allocation methods to improve the performance of the indexing method are also discussed in this paper.