基于Oracle Spatial的空间数据库缓存的关键技术  

Study on Spatial Data Cache Technology Based on Oracle Spatial

作　　者：周芹[1] 李绍俊[2] 宋关福[1] 曾志明[1] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]北京超图地理信息技术公司,北京100101

出　　处：《地球信息科学》2007年第3期40-44,共5页Geo-information Science

摘　　要：Oracle Spatial是目前发展得比较成熟的对象关系型空间数据库存储模型,它实现了空间数据与属性数据的一体化存储,可以定义特定的数据类型,具有开放的存储格式,为GIS数据共享提供新的解决方案;但由于其采用扩展结构的空间数据库模型,对空间数据进行间接存取,数据存储和获取的效率较低。本文在阐述了扩展结构空间数据库模型的优势和局限性的基础上,提出采用缓存技术来提高数据访问效率,重点研究了空间数据库客户端缓存的关键技术,包括缓存实现机制、数据编码方法、数据一致性控制等,并给出实验对比数据,证明了空间数据缓存技术对空间数据尤其是大数据量空间数据的读取上所取得的成效。最后,本文指出了这一技术尚存在的问题及初步解决思路。Oracle Spatial is the extended module of Oracle dealing with spatial objects. The advantage of the extended spatial database model is that it makes the integrative storage of attribute data and spatial data come true, independent of the connection of the two kinds of data. And the open storage format for spatial data provides a new way to access spatial data sharable and reuserable in GIS. But the disadvantage is that the indirect operation of spatial data reduces the efficiency greatly, which becomes the choke point for the GIS application system, especially when the application is massive data oriented. In order to improve data accessing efficiency in spatial database based on extended model, we introduce data cache technology, which has made great contribution to relational database＇s data accessing capability, into extended spatial database model. This article focuses on the application of client-side caching model in extended spatial database and strikes out the sticking points in the process of caching spatial data in client-side, including choices of spatial data to be cached, consistency maintenance of cache data, spatial data coding technology which is available for the users to limit the cache files＇ size in client side, and the basic structure of the cache file. After that, we present some experimental record based on Oracle Spatial. In the conclusion of the article, we point out the main disadvantage of the technology and the continuous work.

关 键 词：缓存 ORACLE SPATIAL 空间数据库 

分 类 号：P208[天文地球—地图制图学与地理信息工程]