Backups : Batch Processing

In a batch processing system the File Generation, Ancestral or Grandfather-Father-Son backup method is used. Remember that in a batch processing system all transactions are entered into a transaction file. This file is then used to update the current master file to produce a new updated master file.

When processing takes place the master file is known as the father file. Processing the father file with the transaction file produces the new master file which is known as the son file.

The father file and transaction file are stored securely. If the son file becomes corrupt the father file can be processed with the transaction file again to reproduce the son file. In this way the father file and its associated transaction file act as a backup of the son file.

An older copy of the master file called the grandfather file is also kept. If the son file and the father file are both corrupted then :

  • The grandfather file and its associated transaction file can be processed to recreate the father file.
  • The recreated father file and its transaction file can then be used to recreate the son file.

Every time processing occurs the tapes are moved back one generation. So the father file becomes the grandfather file and the son file becomes the father file. The old grandfather file is erased to be reused.

GCSE ICT Companion 04 - (C) P Meakin 2004