Abstract:

At present, the uncertain XML index is not completely applicable to continuous uncertain XML data. We propose a continuous uncertain XML index (CUXI) algorithm to support probability threshold range query of continuous uncertain XML data. The algorithm refers to the idea of U Tree, which builds the spatial data index tree in a recursively topdown way. The CUXI index tree constructs a twodimensional data rectangle with the same father’s leaf nodes in XML documents, and the index tree is built accordingly based on the clustering. Leaf nodes calculate in advance and stores some related information of continuous uncertain data. In order to improve query efficiency, a filtering strategy of continuous uncertain data is introduced. When querying, it walks through the index tree to filter the subtrees that do not meet the query range. Experimental results show that the proposed index technique can improve query processing performance to a certain extent.

Key words: continuous uncertain XML;probability threshold range query;CUXI index tree;twodimensional data rectangle;filter