ACC 220 Lecture Notes - Lecture 17: Spooling

• School: McKendree University
• Department: Accounting
• Course: ACC 220
• Professor: Julie Goodin

Document Summary

Current master file (the father) is processed against transaction file to produce new updated master file (the son) The son becomes the current master file (the new father), which is processed against the transaction file to produce new updated master file (the new son) The original file becomes the backup file (the grandfather) When desired number of backup copies is reached, the oldest backup file is scratched (or erased) System designer determines the number of backup master files needed for each application. A single valid location exists for each record. No backup copy of original master file exists. Only the current value is available to the user. The master file being updated is copied to create a backup version prior to each scheduled update run. Backup procedures are scheduled at regular intervals throughout the day. If current master file is destroyed, it can be reconstructed from most recent backup file, but transactions since backup need to be reprocessed.