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传统地质数据管理与应用是参照数据库的外模式来设计数据结构和数据访问接口,在业务逻辑没有发生大的变动情况下,外模式发生更改后,需要修改应用程序才能适应新的数据库结构.鉴于此弊,在关系数据库视图机制的启发下,通过分析不同地质专业地质属性数据的特征,对地质数据库外模式的高度概括,形成用于地质业务分析评价所需的关键属性组成的元组集——控制字典表,基于控制字典抽象出面向地质行业的对象式数据模型、映射数据模型与地质数据的关系,并参照控制字典表的“数据结构”来设计数据访问接口,最终实现地质数据库的动态扩展,无需再修改应用程序,需要做的仅仅是修改控制字典与外模式之间的映射关系,以不变应万变.控制字典作为一个中间件,将用户对地质数据的操作和计算机对地质数据的处理分离开来,充分保证了程序和数据层的逻辑独立性.
Traditional geological data management and application design the data structure and data access interface with reference to the external schema of the database. After the external schema has not changed greatly under the circumstance that the external schema is changed, the application needs to be modified to adapt to the new database structure. In this aspect, inspired by the relational database view mechanism, by analyzing the characteristics of geologic attribute data of different geological specialties, the paper summarizes the patterns of geologic databases and forms the tuple set of the key attributes needed for the geologic business analysis and evaluation - - Control dictionary table, based on the control dictionary abstracted object-oriented data model for the geology industry, mapping data model and geological data, and with reference to the control dictionary table “data structure ” to design a data access interface, and ultimately achieve the geological database Of the dynamic expansion, no need to modify the application, all you need to do is to modify the mapping between the control dictionary and the external mode, in order to maintain the status quo. The control dictionary as a middleware, the user of geological data manipulation and computer The separation of geological data processing, fully guarantee the logic of the program and data layer Neutrality.