1.2 Advantages of Database Systems

Advantages of Database Systems

As shown in the figure, the DBMS is a central system which provides a common interface between the data and the various front-end programs in the application. It also provides a central location for the whole data in the application to reside.

Due to its centralized nature, the database system can overcome the disadvantages of the file-based system as discussed below.

• Minimal Data Redundancy

  Since the whole data resides in one central database, the various programs in the application can access data in different data files. Hence data present in one file need not be duplicated in another. This reduces data redundancy. However, this does not mean all redundancy can be eliminated. There could be business or technical reasons for having some amount of redundancy. Any such redundancy should be carefully controlled and the DBMS should be aware of it.

• Data Consistency

  Reduced data redundancy leads to better data consistency.

• Data Integration

Since related data is stored in one single database, enforcing data integrity is much easier. Moreover, the functions in the DBMS can be used to enforce the integrity rules with minimum programming in the application programs.

• Data Sharing

Related data can be shared across programs since the data is stored in a centralized manner. Even new applications can be developed to operate against the same data.

• Enforcement of Standards

  Enforcing standards in the organization and structure of data files is required and also easy in a Database System, since it is one single set of programs which is always interacting with the data files.

• Application Development Ease

  The application programmer need not build the functions for handling issues like concurrent access, security, data integrity, etc. The programmer only needs to implement the application business rules. This brings in application development ease. Adding additional functional modules is also easier than in file-based systems.

• Better Controls

  Better controls can be achieved due to the centralized nature of the system.

• Data Independence

  The architecture of the DBMS can be viewed as a 3-level system comprising the following:

  - The internal or the physical level where the data resides.

  - The conceptual level which is the level of the DBMS functions

  - The external level which is the level of the application programs or the end user.

  Data Independence is isolating an upper level from the changes in the organization or structure of a lower level. For example, if changes in the file organization of a data file do not demand for changes in the functions in the DBMS or in the application programs, data independence is achieved. Thus Data Independence can be defined as immunity of applications to change in physical representation and access technique. The provision of data independence is a major objective for database systems.

• Reduced Maintenance

  Maintenance is less and easy, again, due to the centralized nature of the system.