A file is a basic unit used to store data on a computer system. Files are saved on storage devices and can contain different types of data such as text, program code, CSV data, images, audio, video, or web pages. Files stored on a computer can be searched and accessed directly. However, when data needs to be processed or displayed through software, appropriate programs must be written to read data from files.

In the school attendance example, student information and attendance records are stored in separate files. One file maintains student and guardian details, while another stores daily attendance records. Although files can store large amounts of data, handling and managing data through a file system becomes difficult as the number of files and volume of data increase.

Limitations of File System

(A) Difficulty in Access
A file system does not provide built-in methods to retrieve data in different formats. Data stored in files can only be accessed through application programs. Since it is not possible to predict all future data requirements, new programs often need to be written to retrieve data in the required manner.

(B) Data Redundancy
Data redundancy occurs when the same data is stored repeatedly in different files. For example, student names may appear in both student and attendance files, and guardian details may be duplicated for siblings. Redundancy leads to unnecessary use of storage space and may result in inconsistencies.

(C) Data Inconsistency
When duplicated data is not updated uniformly across all files, data inconsistency arises. For instance, if a student’s name is updated in one file but not in another, the same data will appear differently. Such inconsistencies are common when files are maintained by different people.

(D) Data Isolation
In a file system, related data is stored in separate files without any direct linkage. As a result, separate programs must be written to access each file. If files are created at different times by different people using different formats, retrieving combined information becomes complex.

(E) Data Dependence
Data in a file system is stored in a fixed structure. If the structure of a file is changed, all application programs that access the file must also be modified. This strong dependency between programs and data structure makes maintenance difficult.

(F) Controlled Data Sharing
Different users such as teachers, office staff, and parents require different levels of access. Ideally, some users should only be allowed to view data, while others can modify it. For example, only teachers should update attendance records, while parents and office staff should have read-only access. Implementing such access control is very difficult in a file system.

20 MCQ’s