Mapxtreme Web Gis Spatial Data Call Methods Research

As people's need with geographical information are increasing, the spacial data involved in Web GIS system has been getting larger and larger, and how to transfer and storage huge data effectively, what is equal to that how to enhance handling data efficiently from the Web Server, which is one of most important aspects in exploituring Web GIS software. Often involve multi-scale, massive spatial data in e-government or public Web GIS application services, particularly public Web GIS service, not only the amount of data, but also has a lot of user. In this application every user is browsing the database to view a small part of all the spatial data stored Web GIS server needs to dynamically according to the specific operation client user, quickly and accurately locate the spatial data user concerned in order to reduce the workload on the data processing and improve service efficiency. And processes this part of the data, then the results are returned to the client's user. In WebGIS, according to the needs of users and different application environment, spatial data server spatial database can be (such as ArcSDE) to manage, you can also manage the documentIn the former mode, the Spatial data call and indexing spatial data can be used ArcSDE spatial indexing mechanism itself to completeBut in the latter approach, design and development of spatial data tend to separate indexing mechanism and call strategy.In this paper, the data organization mechanism and management mechanism, which belonged to some current popular WEB GIS software, were analyzed, and the request and key problems of transferring and maintaining great spacial data under MapXtreme in detail. On the basis of analysis, view and scaling are two control conditions in searching spacial data dynamicly, and the fast transferring mechanism of heavy special data was brought out based on the theory of delaminating the graphics layer; On the other hand, the transferring and management of great capacity for special data was discussed in detail in this research paper, and there was one new menthods of designing indexical graphics levels in order to transfer and organize great capacity of geographical information or data on basis of analyzing the characteristics of organizing spaical data in the background of MapXtreme. In the end, aiming at the maintaining, organizing and transferring great special data in the client under the background of MapXtreme, there was some experiments in the research paper, and summarized the methods of transferring heavy spacail data high effectively.