Tips and best practices for the Online Space Management utility

The Online Space Management utility (OSM) supports several keywords that simplify the management of DEDBs. The following sections describe how to use those keywords to improve the performance of OSM jobs and further simplify management of DEDBs.

Improving performance

Limit the number of UOWs to reorganize: If you specify the number of UOWs to reorganize on the REORGLIM keyword of the SETREORGPARM subcommand, you can minimize the impact on other critical applications that access the area and maximize the effect of reorganization.
For more information, see REORGLIM keyword.
Select the faster run mode for area expansion: If you specify the EXTEND_TYPE=RENAME option for the SETEXTENDPARM subcommand, you can expand the area faster than when you specify EXTEND_TYPE=COPY.
Consideration: If you use the EXTEND_TYPE=RENAME option, after the OSM job runs, you must manually run the OAE Rename program. During the rename process, the area is temporarily stopped in all sharing IMS systems.

For more information, see EXTEND_TYPE keyword.

Using the function more effectively and efficiently

Perform syntax check: If you specify SCAN=YES on the GLOBAL command, OSM does not run the reorganization or area expansion process but it checks the syntax of the control statements, keywords, and parameters that you specify in the JCL. Use this option if you want to verify the syntax of control statements when you create new JCL.
Note: The IMS online system must be started before you submit the job.

For more information, see SCAN keyword.
Select simpler run mode for area expansion: If you specify the EXTEND_TYPE=RENAME option on the SETEXTENDPARM subcommand, you must manually run the OAE Rename program after the job. However, if you specify the EXTEND_TYPE=COPY option, you do not need manual intervention after the job.
For more information, see EXTEND_TYPE keyword.
Perform area expansion multiple times without modifying the JCL job: If you need to expand an area occasionally, specify the expansion size as a percentage. For the IOVF portion, OSM reads the size to expand from the IOVF_UOW keyword. For the SDEP portion, OSM reads the size to expand from the SDEP_CI keyword. OSM accepts integers and percentages. If you specify the values as percentages, you can reuse the job without modification.
For more information, see IOVF_UOW keyword and SDEP_CI keyword.