Change Detection and Maintenance of an XML Web Warehouse

The World Wide Web contains a huge and increasing volume of information. The web warehouse is an efficient and effective means to facilitate utilization of information on the Web, not only to individual users but also to business organizations, especially for decision-making purposes. On the other hand, XML has recently become the new standard for representation and exchange of data on the Web. In this paper, therefore, we study the XML web warehouse and propose an approach to the problems of change detection and warehouse maintenance of an XML web warehouse. This paper has three major contributions. First, we propose an object-oriented data model for XML web pages in the web warehouse as well as system architecture for change detection and warehouse maintenance. Second, we propose a change detection method based on mobile agent technology to actively detect changes of data sources of the web warehouse. Third, we propose an incremental and deferred maintenance method to maintain XML web pages in the web warehouse. We compare by experiments our approach with a rewriting approach to storage and maintenance of the XML web warehouse. Performance evaluation shows that our approach is more efficient than the rewriting approach in terms of the response time and storage space of the web warehouse.