data structure independence

基本解释

It especially made the independence between data accessing structure and data logical structure possible in the database design process.
特别是在数据库设计过程中，实现使数据存储结构与数据逻辑结构的变化独立开来。
Program-data independence:It is a property of database system that the structure of data file is stored in the DBMS catalog separately from the access programs.
数据库目录包含每个文件的结构，每条数据项的类型和存储格式，以及针对数据的不同约束等信息。
In order to keep the data independence from application program, the necessary local logical data structure can be self-defined in every individual application program.
为了实现数据对应用程序的独立性，应用程序自行定义所需要的局部逻辑数据结构。