Efficient label encoding for range-based dynamic XML labeling schemes

Designing dynamic labeling schemes to support ordersensitive queries for XML documents has been recognized as an important research problem. In this work, we consider the problem of making range-based XML labeling schemes dynamic through the process of encoding. We point out the problems of existing encoding algorithms which include computational and memory inefficiencies. We introduce a novel Search Tree-based (ST) encoding technique to overcome these problems. We show that ST encoding is widely applicable to different dynamic labels and prove the optimality of our results. In addition, when combining with encoding table compression, ST encoding provides high flexibility of memory usage. Experimental results confirm the benefits of our encoding techniques over the previous encoding algorithms.