Techniques Of Active Rule In Spatial Database Based On Spatial ECA Model

With the rapid development of spatial information technologies, huge amounts of spatial data have been collected and stored. This explosive growth of data creates the necessity of active rules of spatial database. Active rules provide a general and powerful mechanism for traditional database features. More over, they serve for most new application of database such as version management, workflow control, and web service composition. Therefore, it is important for spatial database to support active service.Among the key issues of realizing active mechanism, how to integrate the active rules and spatial database is most crucial. Combining the spatial database core function can not only ensure performance and reliability of rule processing program, but also improve the efficiency and robust of development of application. Fortunately, existed techniques of traditional database make the implementation of active rules in spatial database feasible.Even though there is a very active research field interested in the spatial integrity constraints, it is still evident the inability of current spatial database regarding the efficient active rules. With the integration of spatial data model and spatial operators, some key techniques of spatial ECA model are discussed. The event detection mechanism, condition evaluation model and problem referring to termination and confluence of rule behavior are researched in this thesis. The main contributions of this thesis are:1. Based on ECA rule mode of traditional database, the sex-tuples of spatial ECA model is defined. First-order logic is used to formally describe spatial integrity constraints, which places the constraint and rules under a uniform mode. The event and condition part are extended by incorporating spatial data model and spatial relation.2. Introducing spatial composite operators, the traditional event expression is extended to spatial fields. An event detect model based on compositional colored Petri net is constructed, which is simple and efficient for describing event expression. Some key issues such as compositional mode of Petri net and inflict resolution are thoroughly discussed.3. The structural of traditional condition evaluation model can not fully utilize spatial query optimization. Combined spatial query optimization in algebra stage with spatial...