Direct File Organization | Database Management System

Direct File Organization | Database Management System

  1. Records are read directly from or written on to the file.
  2. The records are stored at known address.
  3. Address is calculated by applying a mathematical function to the key field.
  4. Such file are created using some hashing function so they are called hashing organization or hashed files.
  5. Files in his type are stored in direct access storage devices such as magnetic disk, using an identifying key.
  6. The identifying key relates to tits actual storage position in the file.
  7. The Computer can directly locate the key to find the desired record without having to search through any other record first,
  8. Here the records are stored randomly, hence the name random file.
  9. It uses online system where the response and updation are fast.

Example:

Any information retrieval system. E.g., Train timetable System.

Advantages of Direct File Organization

  1. Records can be immediately accessed for updation.
  2. Several files can be simultaneously updated during transaction processing.
  3. Transaction need not be sorted.
  4. Existing records can be amended or modified.
  5. Most suitable for interactive online applications.
  6. Very easy to handle random enquiries.

Disadvantages of Direct File Organization

  1. Data may be accidentally erased or over written unless special precautions are taken.
  2. Risk of loss of accuracy and breach of Security.
  3. Special backup and reconstruction procedures must be established.
  4. Less efficient use of Storage Space.
  5. Expensive hardware and Software are required.
  6. High complexity in programming.
  7. File updation is more difficult when compared to that of sequential method.