193 Study on the Query Optimization for the Deep Web Data Integration System

In order to query and retrieve the rich and useful information hidden in the Deep Web efficiently, Deep Web Data Integration Systems (DWDIS) are in active research. To build a practical and useful DWDIS, one of the key problems is to raise the query efficiency. In this paper, by mining the user query logs, adopting the idea of high-speed cache, adding a well-designed local index database in the DWDIS and other steps, a novel optimal query model NDWDIS is presented. Besides, a corresponding strategy for updating the content of the local index database is given and a theoretical qualitative analysis is made of the proposed method.