Date Added: Aug 2009
Reflecting on the history of database management systems reveals that cost-based query optimization has been the dominating method for effectively answering complex queries on large documents. Native XML database management systems provide an efficient infrastructure for storing, indexing, and querying large XML documents. Even though such systems can choose from a huge set of structural join operators and value-based join operators as well as various index access operators to efficiently query XML data, the development of powerful native XML query optimizers is just emerging. Furthermore, it is not known how the aforementioned operators behave in complex XQuery evaluation scenarios, which occur frequently in real-word applications.