Study On The Management Of Soil Information In Chongqing Based On SDE

In geographical information system, the method of storage and management for spatial data is the most important factor upon which the efficiency of the whole system depends. With the increasingly wide implication of geographical information system, larger and larger spatial data should be stored, and this leads to some new problems in the implication of spatial data, such as security, consistency, concurrency and integrality. As a result, the method of storage and management for spatial data transit from commix to integration, which aims to make use of the powerful function of large-scale relationship database management system in the aspects of data storage and management to settle the problems of the storage and management of mass spatial data, optimize the utility of spatial data and improve the application efficiency of the whole system.However, the traditional relationship database management system can't settle the problems of non-structure issues and link of client port and the GIS application program, and to solve these problems middleware and extensive module are developed. Compared with the extensive module in database management system, middleware is the best developed integral management technique for spatial data, which takes the storage model of spatial data in accordance with the criterion of OpenGIS and SQL2 entirely, and SDE, Spatial Data Engine, developed by the environment system institute, is a typical case.Chongqing soil spatial database system is a geoscience's spatial database system with Chongqing soil spatial data as the major spatial data, which targets to realize the integral spatial database for the storage and management of mass spatial data in the environment of network, and combines with the GIS application in client terminal to develop the management and utility system of spatial data in both sever and client terminals.To establish Chongqing soil spatial database system following content should be studied:(1) The system structure of SDE, the storage model and indexing method of spatial data used in SDE;(2) The control method for concurrency based on Oracle and SDE;(3) The control strategy of security and integrity of spatial data;(4) The development method of GIS application in client terminal based on SDE and MapObjects.Soil spatial database is based on Oracle8.1.6. In the terminal of sever, the storage model of SDE Binary is used to store the spatial data. And in the terminal of client, the browser is programmed, with Visual Basic and MapObjects as program environment; furthermore, ArcMap and other application are used to enrich the analysis function of spatial data.Tests indicate that Chongqing soil spatial database system gain the design goal, and show the character of integral spatial data management:(1) Spatial data in wide extension is no longer limited by the size of files;(2) In the environment of network, database management system make the storage of spatial data have lest redundancy and increase the security of spatial data;(3) Through the concurrency control of edition, cooperation of multi-user in the environment of network is realized and work efficiency is increased.