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An Introduction to Transaction Processing
Transaction processing refers to the grouping of a series of changes into a single batch. The entire batch of changes is either accepted or rejected as a group. One of the most common implementations of transaction processing is a bank automated teller machine (ATM) transaction. Imagine that you go to the ATM to deposit your paycheck. In the middle of processing, a power outage occurs. Unfortunately, the bank recorded the incoming funds prior to the outage, but the funds had not yet been credited to your account when the power outage occurred. You would not be very pleased with the outcome of this situation. Transaction processing would prevent this scenario from occurring. With transaction processing, the whole process succeeds or fails as a unit.A group of operations is considered a transaction if it meets the following criteria:
- It is atomic .
The group of operations should finish as a unit or not at all. - It is consistent .
The group of operations, when completed as a unit, retains the consistency of the application. - It is isolated .
The group of operations is independent of anything else going on in the system. - It is durable .
After the group of operations is committed, the changes persist, even if the system crashes.
If your application contains a group of operations that are atomic and isolated, and if, to maintain the consistency of your application, all changes must persist even if the system crashes, you should place the group of operations in a transaction loop. With Access 2003, the primary benefit of transaction processing is data integrity.
