March 31, 2007 16:13 WSPC- Proceedings Trim Size: 9in x 6in swiis Using Semantics in XML Data Management

XML is emerging as a de facto standard for information exchange over the Web, while businesses and enterprises generate and exchange large amounts of XML data daily. One of the major challenges is how to query this data efficiently. Queries typically can be represented as twig patterns. Some researchers have developed algorithms that reduce the intermediate results that are generated during query processing, while others have introduced labeling schemes that encode the position of elements, enabling queries to be answered by accessing the labels without traversing the original XML documents. In this paper we outline optimizations that are based on semantics of the data being queried, and introduce efficient algorithms for content and keyword searches in XML databases. If the semantics are known we can further optimize the query processing, but if the semantics are unknown we revert to the traditional query processing approaches