基于多级模式的地形数据库变化信息发布方法

Method of publishing change information of topographical database based on multi-schema

为了解决地形数据更新以后,及时将地形数据的变化信息发布给用户的问题,研究了新的变化信息发布方法,提出了基于图元模式、要素模式和用户视图3级结构的地形数据库变化信息发布方法:基于图元建立变化信息的图元模式,通过组合图元模式中的记录构建变化信息要素模式;并根据用户的具体需求,通过组合和筛选图元模式和要素模式中的数据构建用户视图。此方法能有效的满足用户对各种变化信息的需求。

When the topographic data arc updated, the change information must be published to the end-users. In order to solve this problem, the recorded change information is based on the element that is the representation of the part of the whole topographic feature-the element schema of change information. But the users always want to know the change information of some whole features-the users＇ views. There is a conflict between the element schema and the users＇ views. In order to solve the problem, this paper proposes a three-level schema of publishing changed information of topographical database： firstly, establishing the element schema of change information based on the element, and then dynamically establishing the feature schema of changed information.