Space-time Analysis Algorithm Of The Database Stadbs Analysis Operations And Query Language

The spatio-temporal analysis operations are one of the most important functions in spatio-temporal databases. Starting from the data model, we classify all kinds of operations related to the attributes of time and space in detail. According to whether the object concerned has the attribute of time, the operations for spatio-temporal objects can be divided into two classes, one generated directly from the temporal types, and the other generated from the non-temporal types, which act on spatio-temporal objects at last after temporal lifting. All operations are discussed, including implementation of the algorithms. Among these operations, the queries on the topological relationships between two moving objects are the most important, which we pay more effort to analyze. On the basis of the topological theory of spatial objects, we give abstract definitions of various basic spatio-temporal topological predicates by integrating the factor of time; then developed from the basic level, for the purpose of reflecting sufficiently the dynamic nature of spatio-temporal objects, complex topological predicates are explored; at last, based on the data structure of AVL used for moving objects, spatio-temporal topological analysis algorithms are specified, which makes the use of the concept of Realms and ROSE algebra and is implemented by integrating Plane Sweep algorithm with the factor of time interval. From the discussed functions and predicates, we give some applications of Spatio-Temporal Query Language. Finally, an interface of the visual editor for STADBS is presented.