Size and speed

Overview | Interactive On-line | Batch
Data processing

Overview

Processing time of the different programs bears little relation to their size - it is dependent on the number of records being processed, and how these records are input and output. eg printing of statements is dependent on the speed of the printer, or updating a master file is often dependent on how well the file is organised on disk.

Interactive on-line

A simple inquiry may take less than 5 seconds, though the program may be resident in memory for the whole working day.

Batch

A statement print program may take 3 hours or more, but unlike the inquiry program, is removed from the computer's memory when completed. (So which then 'Inquiry or Statement' takes longer?)

The update program, is the largest most complicated program, partly because the controls that are built into it to make sure data and records do not get lost.

Validation can be quite bulky if multiple inter-related tests are required.