Introduction to Transaction Processing

Transaction processing is a style of computing that is divided into individual, indivisible operations, called transactions. In a transaction, either the work performed succeeds or fails as complete unit.

A transaction processing system allows application programmers to concentrate on writing code that supports the business, by shielding application programs from the details of transaction management:

• It manages the concurrent processing of transactions.
• It enables the sharing of data.
• It ensures the integrity of data.
• It manages the prioritization of transaction execution.

When a transaction starts processing, CICS runs a program that is associated with the transaction. That program can transfer control to other programs in the course of the transaction, making it possible to assemble modular applications consisting of many CICS programs.

At any time, in a CICS system, many instances of a transaction can run at the same time. A single instance of a running transaction is known as a task.