Processing XML Path Expressions Using XML Materialised Views

Recently, semantic caching for the database-backed web applications has received much attention. The results of frequent queries could be cached for repeated reuse or for efficient processing of the relevant queries. Since the emergence of XML as a standard for data exchange on the web, today’s web applications are to retrieve information from the remote XML sources across the network, and thus, it is desirable to maintain the XML query results in the cache for the web applications. In this paper, we investigate the problem of processing an XML path expression, which is one of the core features of XML query languages, using the XML cache maintained as materialised views. Algorithms to rewrite the given XML path expression using its relevant materialised view are proposed. Also provided are the implementation details of how an XML path expression is processed with its relevant XML materialised view when a relational DBMS is employed for storing XML base documents as well as their materialised views. The preliminary experimental results show that our scheme is feasible and promising.