Prefix based numbering schemes for XML: techniques, applications and performances

Commonly used in network routing, programming, classification and knowledge representation systems, labeling schemes have also interested the XML community. We thus motivate and describe numbering schemes, their applications, and the trade off between storage capacities and runtime performance. We present a taxonomy of numbering schemes for XML based on the types of supported queries (ancestor, adjacent, etc), the encoding technique, and whether the scheme offers robustness properties according to updates. We describe some of the numbering techniques proposed for XML. We focus on prefixbased schemes. We give a qualitative comparison of the existing numbering schemes, discussing their advantages and drawbacks. Then, we compare their storage requirement and performances. Finally, we consider the new research directions that are likely to benefit from numbering scheme techniques.