A Structural Numbering Scheme for XML Data

Identifier generation is a common but crucial task in many XML applications. In addition, the structural information of XML data is essential to evaluate the XML queries. In order to meet both these requirements, several numbering schemes, including the powerful UID technique, have been proposed. We introduce a new numbering scheme based on the UID techniques called multilevel recursive UID (rUID). The proposed rUID is robust, scalable and hierarchical. rUID features identifier generation by level and takes into account the XML tree topology. rUID not only enables the computation of the parent node's identifier from the child node's identifier, as in the original UID, but also deals effectively with XML structural update and can be applied to arbitrarily large XML documents.