The GIS-Based Spatial Data Query Technology And Its Applications

With the fast development of the computer technology and the expanding of the social demand, the application of GIS becomes more and more popular. The storage and query of large amount of spatial data are the key problems in the construction of GIS systems .This dissertation first discusses spatial data characteristics, and introduces spatial data models, spatial data structures and spatial indexes , and focus on the spatial data cache technology and the fast inquiry implementing agent technology and then analyzes the advantages of taking Agent technology to solve the problems such as the Network bandwidth dependence, the stability of data service, and query speeds which occur in the GIS spatial data. This dissertation also discusses Agent-based Spatial Data Query Model-ABSQM, which is designed according to Agent. ABSQM makes out a new solution to GIS spatial data query, as it takes advantage of Agent's intelligence, autonomy, and mobility. It takes spatial data cache technology to establish the large capacity cache area for the backstage database, and to cushion customers'visiting request to the database, so as to reduce the frequency of the server access. In this way, the searching efficiency of the database system shall be improved.An application based on the ABSQM, General Air flight Scheduling and Optimizing Management Simulator System (GASOMS) is implemented. The system performance is evaluated next. And finally, some suggestions for the improvement of the application system are given.