基于关系数据库的栅格数据存储和访问技术研究

提出了基于关系模型和OLE／COM的栅格数据库解决方案。栅格数据及其元数据存储在关系数据库中，使用OLE DB Profider进行客户端和数据库服务器之间的连接；数据访问模型参考OpenGIS的相关规范和其他相关产品的实现方法设计，并使用COM作为实现技术。此外，通过在数据存储方面采取分块存储、建立金字塔结构、进行数据压缩等策略，在数据访问模型方面建立数据缓冲区及智能更新机制，以改善系统的运行效率。以上方案和优化措施在基础GIS组件系统ComGIS中做了相关的实现；实践证明，这种解决方案基本上解决了基于关系数据库的栅格数据存储和访问问题。

Researches on Storage and Access Technologies of Raster Data in Relational Database

This paper is mainly about the raster database solution based on the RDBMS and OLE/COM technologies. Raster data and its metadata were stored in commercial relational database, using tables of particular schema. A COM component was developed to access and render the raster data stored in RDBMS, with the OLE DB providers as the connection bridge. Some special measures, such as tiling storage, pyramidal structure, data compression and intelligent data buffer, were also carried out to improve the performance. The technologies cited above were designed according to OGC specifications and other relative commercial products. They were also applied to the basic GIS Component System ComGIS and performed well.