Query Optimization against XML Data

Web services allow middleware access to a relational database and require data representation in XML format. The XML views obtained from relational databases can be accessed by using XPath queries. This article proposes an optimization model for XML data processing based on a heuristic algorithm to extract data from XPath views. To this end, the author uses various XPath query classes temporarily stored in cache, as XPath views. For each view selected from cache, a compensation query can be found and composed with in order to solve an XML data query. Experimental results reveal the effectiveness of the heuristic method used to solve queries on XML documents.