摘要： 当空间应用进入到网络化后，人们迫切需要利用数据库的约束机制为空间数据提供更好的保护，目前数据库系统只能管理单一分辨率的地形空间数据。该文提出了一种可在关系数据库顶端实现的、支撑动态多分辨率地形与可视化数据调用的关系模型。该模型解决了在大规模地形可视化程序中，数据库系统客户端/服务器间的数据交换问题，利用了X树索引技术将多分辨率地形映射到关系模型中，利用特征空间将累进查询过程转换为几个简单的一维范围查询的联合，在各表中每个帧分别进行一次索引扫描，即可获得全部必要的数据，使其更好地处理大规模的地形数据。实验结果表明，利用该模型能够获得良好的检索效果。

关键词: 多分辨率索引, 地形可视化, 关系数据库, 空间索引

Abstract: As spatial application goes into network environment, the database support is needed to protect spatial data source from security and concurrent access problem. As for conventional spatial database access methods are typically based on single resolution only, the paper proposes a relational model supporting dynamic multi-resolution terrain visualization to speed up the retrieve of terrain dataset and to overcome the bottle-neck of data exchange between server and client. The X-tree index technology is applied to mapping multi-resolution terrain expression in relational model. The progressive query is translated into the union of several simple one dimensional range queries with help by feature spaces conception. Only one time of scan is needed to obtain all of necessary data for every table in a frame, makes it more suitable to handle large scale terrain dataset. The experiment results show its perfect index results.

Key words: Multi-resolution index, Terrain visualization, Relational database, Spatial index

中图分类号: 

• TP391.41