Limitations of File Based System
The file-based system has some limitations. The limitations are listed as follows:
- Isolation and separation of data: When the data is stored in separate files it becomes complex to access. It becomes very complex when the data has to be retrieved from more than two files as a large amount of data has to be looked for.
- Duplication of data: Because of the decentralised approach, the file system varies to uncontrolled duplication of data. This is disagreeable as the duplication leads to wastage of a lot of storage space. It also money and cost times to enter the data more than once. For instance, the address information of student may have to be duplicated in bus list file data.
- Inconsistent Data: The data in a file system can become inconsistent if more than one person changes the data simultaneously, for example, if any student changes the residence and the change is notified to only his/her file and not to bus list. Putting wrong data is also another reason for inconsistencies.
- Data dependence: The physical structure and storage of data files and records are distinct in the application code. This means that it is very difficult to make changes to the existing structure. The programmer would have to recognize all the affected programs, change them and retest them. This characteristic of the File Based system is known as program data dependence.
- Incompatible File Formats: As the structure of the files is embedded in application programs, the structure is fully dependent on application programming languages. Therefore the structure of a file generated by COBOL programming language may be quite dissimilar from a file generated by 'C' programming language. This incompatibility makes them hard to process together. The application developer may have to develop software to change the files to some common format for processing. Though, this may be time consuming and expensive.
- Fixed Queries: File based systems are very much dependent on application programs. Any report or query needed by the organisation has to be developed by the application programmer. With type, the time, and number of queries or reports increases. Producing dissimilar types of queries or reports is not possible in File Based Systems. As a result, in some organisations the kind of queries or reports to be produced is fixed. No latest query or report of the data could be produced.
Besides the above, the maintenance of the File Based System is complex and there is no provision for security. Recovery is non-existent or inadequate.