Effective Evaluation of XML Queries in a Visual Environment-

 Since its emergence in 1997, Extensible Markup Language (XML) has become a standard data format for data exchange among a variety of web applications. In this paper, we present a framework to effectively evaluate XML queries in a visual environment. We have developed a system termed VXPath, which is a visual XPath query evaluator that allows the user to evaluate various XPath queries by clicking the nodes in an expanding tree instead of typing the whole XPath queries manually. Our system GUI is built on top of Microsoft .NET Windows Forms Applications. We have implemented most XPath axes in our system, including child, descendant, self, parent, ancestor, following-sibling, preceding-sibling, predicate and so on. In order to handle large size XML documents, instead of loading the whole XML document into memory, we developed an effective algorithm to extract a concise data synopsis called structural summary from the original XML document to avoid the loading overhead for large XML documents. We evaluated our system over the data from XMark and DBLP and our system can handle large XML documents up to gigabytes.