【作者】 徐娟； 李战怀； 王彦龙；

【机构】 西北工业大学计算机学院；

【摘要】 <正>1引言XML已经成为互联网上数据表示和交换的标准,大量的XML文档出现在网络中,有效地存储XML数据并提供高效的XML数据查询,成为当今急需解决的问题。目前,大部分有关XML数据的索引和查询技术都是基于某种对XML文档树的编码技术,区间编码是一种主流的编码方式。更多还原

【Abstract】 Region encoding scheme is popular to label XML tree.However,inserting nodes or subtree will cause abundances of nodes renumbering.Focusing on this issue,we propose a new encoding scheme with the consideration of update cost,which is the number of renumbering nodes after update.By analyzing the demands of preserving coding space for different nodes in XML document tree,we draw a conclusion that the smaller preorder numbering is, the bigger preserving coding space is,and vice versa.From the theoretical analysis,the structural relationship between two nodes,such as parent-child relationship,ancestor-descendant relationship and sibling relationship,can be determined in constant time-bounding.Further more,compared with the existing encoding schemes,the proposed scheme is convenient for the insertion of nodes or subtree and can well resolve the problem of renumbering abundance after update.更多还原