当一个数据库管理系统被使用时，有关数据管理组织的详细情形不必被建立在每一个应用程序中：应用程序通过文件名向数据库管理系统要数据。-The multiple-database model is represented by proposals for shared and private database architect rues, checkout and checking of data to and from shared and private databases．Each user may populates/her private database with data checked out of the shared database, perform updates against the data. and check them back into the shared Database.