A formal algebra is essential for applying standard database-style query optimization to XML queries. We propose a spatiotemporal XML data model and develop such an algebra based on Native XML, for manipulating spatiotemporal XML data. After studying NXD spatiotemporal database and query framework, formal representation of spatiotemporal query algebra is investigated, containing logical structure of spatiotemporal database, data type system, and querying operations. It shows that the model and algebra lay a firm foundation for managing spatiotemporal XML data.
XDTM: The XML Data Type and Mapping for Specifying Datasets
