| Since XML's introduction, this new eXtensible Markup Language, has quickly emerged as the universal format for publishing and exchanging data in the World Wide Web. As a result, data sources, including object-relational databases, are now faced with a new class of users: clients and customers who would like to deal directly with XML data rather than being forced to deal with the data source particular schema and query languages. XML is also rapidly becoming popular for representing web data as it brings a finely granulated structure to the web information and exposes the semantics of the web content. In all these web applications including electronic commerce and intelligent agents, view mechanisms are recognized as critical and are being widely employed to represent users' specific interests. Rewriting the user queries using views is a powerful technique in the above described applications, which can be categorized as data integration, data warehousing and query optimization. The current implementation experiments the feasibility of using rewritings for query processing in semistructred data. Experiments showed that computing rewriting is very time efficient even for mane views as for example 500 views. The implementation is using automata. |
