开放式空间数据库访问接口的开发应用

GIS应用的快速发展对异构空间数据库互联互访提出了更高的要求。本文对现有的多种异构空间数据库互操作模式进行了对比分析,指出了各种模式的特点及其不足,在此基础上,提出了一种开放式空间数据库互联互访(OGDC,Opening Geospatial Database Connectivity)的策略与规范,以及由各家GIS平台软件厂商共同制定标准接口,再由数据库开发厂商或数据提供厂商按照标准接口进行开发实现的新模式。本文对OGDC的设计思路、技术特点和应用情况进行了分析,设计了地理空间数据库的数据访问对象模型及接口,并使用国产空间数据库软件BeyonDB,对OGDC作了开发和实验验证。实验表明,OGDC可以较好地兼顾空间数据互联互访中系统功能、效率和易用性等方面的需求,为异构空间数据库的标准化共享和持续利用提供了一种较为可行的解决方案。

Study on Opening Geospatial Database Connectivity

With the fast development of GIS technology and improvement of the GIS application technology, higher requirements have been put forward to the spatial database connectivity and accessibility. This study first proposes a comparative analysis on cross-sectoral large-scale shared connection to spatial database, thus to point out the hard-to-achieve synchronization updating during different data types conversion. Direct data access model cannot be fully compliance with the data type updating. The spatial extension model of the relational database is dissatisfactory in performances as well as professional spatial analysis. The support of Web Service model is insufficient for non-standard spatial data types; the protocols provided by software providers are of great specificity and difficulty to be extended by third parties. Then in this article, the interfaces of heterogeneous databases connectivity are analyzed deeply. Currently there are two categories of interfaces which are the relational database access interfaces and spatial database standard interfaces. Based on the analysis, the article proposes the ‘Opening Geospatial Database Connectivity (OGDC)’interfaces mechanism and specifications to provide a completely new model that a series of standard interfaces provided by several GIS platform software providers is jointly realized by database providers or data providers based on these standard interfaces. Detailed introductions are presented for the OGDC designs, technical features, implementation techniques, and applications. Finally, the feasibility and advantages of these proposed standards and specifications are demonstrated by a prototype using the OGDC from the domestic-developed distributed spatial database software‘BeyonDB’. And the prototype shows that OGDC could perfectly take account of the functionality, the efficiency and the usability of the spatial database connectivity, thus to provide a new application model for the standardized sharing and continual utilizing of the heterogeneous spatial database.