Data Redundancy
Data redundancy means duplication of data in multiple files. Data redundancy causes wastage of storage. In the file processing system, the same data may be duplicated in several files.
Suppose that two files are used in a college. The student’s file contains the data such as Roll No, Name, Address, Phone, and other details of the student. The Library file contains the same date of the students who borrow books from the library along with the information about the book. The date of one student appears in two files. It causes wastage of storage and creates many problems
2 Date Inconsistency
Date redundancy in the file system causes the problem of data inconsistency. Data inconsistency means that two files may contain different data about the same entity. For example, the address of a student must be updated in all files if any change occurs. It is possible that it is changed in the students’ file but not in a library file. The data become inconsistent in this situation
3 Program Data Dependency
Program Data Dependency is a relationship between data in the file and the program used to update and maintain the file. The application programs are developed according to a particular file format in the files managements system. The application programs have to be changed if the format of the file is changed. For example, if the is a change in the length of the postal code, it requires a change in the program. The changes may be costly to implement,
