File-based information systems and their limitations

 

 

A file based information system is a collection of application programs that perform services for users wishing to access information. Each dataset within a file-based system is defined and managed by a separate program. Because of this, there are limits as to how that data can be used or transported. File based systems were developed as better alternatives to paper based filing systems. By having files stored on computers, the data could be accessed more efficiently. It was common practice for larger companies to have each of their departments looking after their own data.

The problems that arise with this type of file based system are listed below:

  •  Data separation and isolation – Difficult to access data that is available (eg. from two files – Student that achieved good academic result and active in extra-curricular activities too.

  • Limited Data Sharing – Data are scattered in various files, which may have different formats. These files may be stored in different folders may be on different computers located in different departments. So, due to this data isolation, it is difficult to share data among different applications.

  • Poor data control – File systems have no centralized control of the data descriptions.  Tables and field names may be used in different locations to mean different things.  For example, the DSW files may list a student as having a single Name field that is made up of students’ Initial and Last name eg S Ahmad.  The Proctorial department may keep the students’ name in three separate fields; First name, Initial, Last Name. This may make it difficult to compare the data in the two files or at least require additional time in programming the comparison.

  • Data dependence – File structure is defined in the program code. It is difficult to make changes to an existing data structure.

  • Data duplication – Entering data more than once translates into more time and money. Additional storage space is needed. Duplication also leads to inconsistencies. When files are duplicated and held in a number of locations situations can arise that will cause data to be inconsistent.

  • Corrections or modifications made in one location may not be updated in another.  For example, student address files held by the Accounts Department may be updated while those held by the Dean of Faculty are not updated. 

  • Modifications made to data files may also lead to less obvious discrepancies.  For example a town name may be spelt differently in two locations eg Askot and Askote. 

  • Incompatible data (different file formats) – Programs are written in different languages, and so cannot easily access each other’s files.

  • Lack of flexibility in organizing and querying the data – Fixed Queries. Programs are written to satisfy particular functions. Any new query needs a new program.

  • Atomicity Problems – Any operation on a database must be atomic. This means, it must happen in its entirely or not at all.

  • Security Problems – Database should be accessible to users in limited way – each user should have access only to data concerning his requirements. This is not easily accomplished in file-based information systems.

  • Application Programs – Increased number of different application programs.

  • Inadequate data manipulation capabilities: Data in traditional file systems is not easily related, particularly if the files have been developed for separate purposes.  If the organization requires information to be generated that accesses data from several unrelated files the task may prove difficult or require re-entry of data. For example, in a library the catalogue of books may be held in one file.  Books on order for the library may be held in another file.  When books are received the catalogue will need to be manually updated if the two files are not related.

  • Lengthy development times: Each new application requires development of the program along with the development of the relevant files for that application.  Although the data may be held elsewhere in the organization the data will need to be imported or re-entered into the new files.  This takes time.  As organizations grow and change they need to change their internal applications quickly to meet new demands.  Lengthy development times are a disadvantage.

As against these limitations, some advantages of database systems are outlined below:

  • Sharing of data

  • Consistency of data

  • Integrity of data

  • Security of data

  • Data independence

  • Allows for more analysis of the same amount of data

  • Improved data access and system performance

  • Potentially increased productivity

  • Increased concurrency

  • Improved data backups and recovery

 Ref: https://www.dlsweb.rmit.edu.au/toolbox/Database/Certificate4_DB_Toolbox/content/dbsystems/file_process.htm

Notes & Handouts

The Himalayas

Kumaon Himalayas

Askot Basemetals

University

   


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