Approximate query algorithm based on eight-neighbor grid clustering for heterogeneous XML documents

An approximate query algorithm based on eight-neighbor grid clustering for heterogeneous XML documents is proposed. Firstly, the cost models of three editing operations used to compute semantic distance between XML documents are given. Secondly, by using the semantic distance, vector models of XML documents are built, and eight-neighbor grid based clustering algorithm for XML documents is designed. Thirdly, the query evaluation strategy for the static order-selective algorithm is optimized with the physical and logical clustering centers obtained from the process of clustering, thus the cluster center can only be located and queried within a local area of document groups without extending all over XML documents, and the query results satisfying the users' requirements can be returned rapidly. The experiments of intelligent design of automobile shape show that compared to static selectivity order algorithm, the efficiency of the algorithm is increased averagely by 3-4 times.