Comparison of Traditional File-Based Approach and Database Approach
At the beginning, you should understand the rationale of replacing the traditional file-based system with the database system.
File-based systems were an early attempt to computerize the manual filing system. File-based system is a collection of application programs that perform services for the end-users. Each program defines and manages its data.
However, five types of problem are occurred in using the file-based approach:
Separation and isolation of data
When data is isolated in separate files, it is more difficult for us to access data that should be available. The application programmer is required to synchronize the processing of two or more files to ensure the correct data is extracted.
Duplication of data
When employing the decentralized file-based approach, the uncontrolled duplication of data is occurred. Uncontrolled duplication of data is undesirable because:
Duplication is wasteful
Duplication can lead to loss of data integrity
Using file-based system, the physical structure and storage of the data files and records are defined in the application program code. This characteristic is known as program-data dependence. Making changes to an existing structure are rather difficult and will lead to a modification of program. Such maintenance activities are time-consuming and subject to error.
Incompatible file formats
The structures of the file are dependent on the application programming language. However file structure provided in one programming language such as direct file, indexed-sequential file which is available in COBOL programming, may be different from the structure generated by other programming language such as C. The direct incompatibility makes them difficult to process jointly.
Fixed queries / proliferation of application programs
File-based systems are very dependent upon the application programmer. Any required queries or reports have to be written by the application programmer. Normally, a fixed format query or report can only be entertained and no facility for ad-hoc queries if offered.
File-based systems also give tremendous pressure on data processing staff, with users' complaints on programs that are inadequate or inefficient in meeting their demands. Documentation may be limited and maintenance of the system is difficult. Provision for security, integrity and recovery capability is very limited.
In order to overcome the limitations of the file-based approach, the concept of database and the Database Management System (DMS) was emerged in 60s.
A number of advantages of applying database approach in application system are obtained including:
Control of data redundancy
The database approach attempts to eliminate the redundancy by integrating the file. Although the database approach does not eliminate redundancy entirely, it controls the amount of redundancy inherent in the database.
By eliminating or controlling redundancy, the database approach reduces the risk of inconsistencies occurring. It ensures all copies of the idea are kept consistent.
More information from the same amount of data
With the integration of the operated data in the database approach, it may be possible to derive additional information for the same data.
Sharing of data
Database belongs to the entire organization and can be shared by all authorized users.
Improved data integrity
Database integrity provides the validity and consistency of stored data. Integrity is usually expressed in terms of constraints, which are consistency rules that the database is not permitted to violate.
Database approach provides a protection of the data from the unauthorized users. It may take the term of user names and passwords to identify user type and...
Please join StudyMode to read the full document