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Data independence separates data from programs to ensure stability and prevent corruption. It limits access to data storage and allows for logical and physical independence, making database management easier. This differs from data dependency, where data is represented in source code and can be changed by programs.
Data independence is a form of database management that keeps data separate from all programs that use it. As the cornerstone of the idea of a DBMS or database management system, this independence ensures that the data cannot be redefined or rearranged by any of the programs that use it. This way the data remains accessible, but is also stable and cannot be corrupted by applications.
In a centralized DBMS environment, database management is based on the data independence process. While data transparency still exists regarding the ability of different applications to access and use the data to complete tasks, no one program or application can read and then start making changes to the data itself. Information consistency makes the overall process of maintaining and managing a single database or multiple databases within a single environment much easier.
This concept is different from another approach called data dependency. With this approach, the data used to run an application is actually represented in the program’s source code. The ability of data to be changed by the program, and vice versa, means that the information is not considered constant and can be changed either by initiating the change through source code changes or by using the program in other ways to adjust the underlying data.
One of the functions of data independence is to limit access to the data storage facility by user applications. By effectively hiding the specifics of the structure from applications, it becomes impossible for any application to alter the nature of the data. As a result, essential data maintains its integrity and remains consistent regardless of how many databases or database applications access it.
There are two basic levels or types of independence when it comes to data. Logical independence of the data allows the structure of the data to change regardless of whether the applications or programs that use the data change. There is no need to rewrite current applications as part of the process of adding or removing data from the system.
The second type or level is known as physical data independence. This approach has to do with altering the organization or storage practices related to the data, rather than changing the data itself. Implementing this change in file organization or in the indexing strategy used for data does not require any changes to the external structure of the applications, which means that application users will not notice any difference in the function of their programs.
