Batch processing, spooling, real time control and transaction

Batch processing, spooling, real time control and transaction

1. One or more programs submitted to computer as a job, put into queue for processing

   • Batch processing is normally associated with mainframes, but PCs running Windows can create batch files, in which are run using job - scheduler at predefined times

2. No interaction between computer and user

   • Therefore some processes can be done of peak times

3. Examples

   • A job might be a payroll run for a company together with all the time-sheet details of the workers for that week (hours worked, overtime etc).
   • Electricity bills are produced using a batch processing system. All the meter readings from premises that use electricity are collected together and processed as a batch.

4. Real time control

   • Where data is immediately processed, stored data is updated and any necessary actions taken.
   • The computer used is dedicated, no other things are done
   • Examples
     • Process-Control System.
       • Input data received from sensors is processed immediately, analysed and any necessary actions taken without any delay.
         • Many modern manufacturing processes are real-time systems controlled by computers.
     • a flight simulator. a computer guided missile air traffic control system

5. Real time transaction

   • An on-line system in which individual, discrete transactions are processed as they occur.
   • When a transaction is received by the computer, the data stored is immediately updated.
   • if if you look at the state of the system at any instant it is always up-to-date.
   • means that if if you look at the state of the system at any instant it is always up-to-date
   • Examples : a holiday booking system a supermarket stock control system an on-line Internet shop

6. Spooling

   • Items are sent to a hardware device and stored in a queue for processing.
   • e.g. printer queue
   • Spooling is needed because of the difference in speeds between peripherals and processors (printers are very slow compared to processors).
   • more than one computer to use the same printer. user can carry on working while waiting for a print job to finish is fair. Documents are printed in the order they are received.

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