Batch processing
From Free net encyclopedia
Batch processing is the sequential execution of a series of programs ("jobs") on a computer.
The term, "batch", originated in the days when programmers wrote code on paper forms which would be keypunched onto 80-column punch cards or paper tape. The cards or tape would then be passed to the system operator ("sysop") who would schedule the task, and at a later stage feed the program into the computer. Because a number of tasks would be 'batched' together rather than be put into the system immediately the tasks were referred to as "batch jobs".
Batch jobs are set up so they can be run to completion without human interaction, so all input data is preselected through scripts or commandline parameters. This is in contrast to interactive programs which would prompt the user for such input.
Batch jobs are not thought of as interactive, but transaction processing systems such as IBM's CICS may run from a technical perspective as batch jobs, although this is typically obscured from terminal users.
Batch processing has these benefits:
- Allows sharing of computer resources among many users
- Time shifts job processing to when the computing resources are less busy
- Avoids idling the computing resources without minute-by-minute human interaction and supervision
- It is used on expensive classes of computers to help amortize the cost by keeping high rates of utilization of those expensive resources.
The batch processing historically been synonomous with mainframe computers. Since this class of computer was so expensive, batch processing was used for the reasons listed above. Also, in the early days of electronic computing, interactive sessions with computer terminal interfaces (and later Graphical user interfaces) were not yet widespread.
The term batch has now become synonomous with the UNIX operating system, it has strong utilites within the Operating System that allow various computing tasks to be run in a controlled and orderly manner.