提出了适用于XMl文档更新环境下的区间编码方法——dClS(dynAMIC COnTAInMEnT lAbElIng SCHEME).dClS将基于整数的编码泛化到基于向量的编码,扩展了传统静态区间编码方法,有效避免了XMl文档更新时的重新编码.不论文档更新与否,dClS都显示了良好的性能:dClS利用基于整数的静态区间编码方法进行初始编码,在文档不更新的环境下,具有较高的存储效率和查询性能;同时,dClS将整数视为特殊向量,不仅能够支持文档更新,而且更新效率高;特别是倾斜插入时,dClS可以避免编码位长的快速增加.实验结果表明,与已有的动态区间编码方法相比,dClS具有更好的性能.A novel containment scheme called DCLS is proposed to effectively process updates in dynamic XML data.DCLS generalizes the static containment scheme from integer order to vector order and thus completely avoids re-labeling when XML data updating.Moreover,DCLS is compact and efficient regardless of whether the documents are updated or not.On the one hand,DCLS uses integer-based static containment scheme for initial labeling,which yields compact size and excellent query efficiency for static documents.On the other hand,DCLS takes the integer as special vector,which not only deals with the case of document updating,but also achieves high query performance.Most importantly,DCLS can effectively avoid the rapid increase of labeling size for the case of skewed insertions.Experimental results confirm the benefits of this approach compared to previous dynamic containment schemes.国家自然科学基金(50604012);中央高校基本科研业务费专项资金(2011121049
