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Use

Before you decide on a save strategy for your SAP system, you need to be familiar with the concepts of journaling and commitment control.

Journaling

This refers to the recording of any changes made to database files. Journaling enables commitment control (see below) to work, and it enables you to apply or roll back these changes if required.

Journaling is used for commitment control and recovery. The system records the changes made to database files in a journal receiver.

Journaling is a requirement for running SAP systems and is automatically started when you install an SAP system.

Note

You can keep the libraries that contain the database objects, and their associated journal receivers in different auxiliary storage spools (ASPs). This enables data recovery after disk failures that result in a loss of the ASP which is holding the database libraries. This may be desirable for production systems that are not protected by high availability or disaster recovery solutions based on two independent copies of the database libraries. For more information, see SAP Note 654801 Information published on SAP site.

There are two methods of managing journal receivers, depending on your chosen save strategy:

  • Save Strategy 1: Restoring and Recovery

  • Save Strategy 2: Restoring Only

Commitment Control

Commitment control allows you to process a group of changes to resources as a logical unit of work.

For the SAP system, commitment control is always active. This means that the system processes a group of changes to database files as a single transaction. While journaling on its own allows you to ensure that only changes to the last record processed are lost in the case of a system failure, journal management combined with commitment control enables the system to ensure that all changes within a transaction are completed or rolled back if processing is interrupted.