As too many functions existed in EDB, we divided whole system by operation hierarchy, i.e., Interface Process Module, Database Engine Module, Data Access Module, Database Service Module and Data Store Module.

• 由于EDB中功能较多，我们将该系统的体现结构按照操作的层次进行了模块划分：接口处理层、数据库引擎层、数据存取层、数据库维护模块和数据存储模块。