RDE maintenance at database reorganization

Two types of reorganization are supported for IMS databases: reorganization without a DBD change and reorganization with a DBD change.

For a database reorganization without a DBD change, DMB verifications run while the database is being unloaded and reloaded by using the same DMB information. Because Integrity Checker uses the same RDE, the RDE does not need to be updated.

For a database reorganization with a DBD change, the first DMB verification is done while the database is being unloaded. For this DMB verification, Integrity Checker uses the DMB information before the DBD change. The second DMB verification is done while the database is being reloaded. For this DMB verification, Integrity Checker uses the DMB information that reflects the DBD change. Therefore, before the database is reloaded, the RDE must be re-created by using the updated DBD information.

If you use one of the following tools to reorganize the database, Integrity Checker automatically creates an RDE that contains the DMB information that reflects the DBD change:

IMS HISAM Reorganization Reload utility
IMS HD Reorganization Reload utility
IMS Database Reorganization Expert
- Smart Reorg utility
- IPR Reload utility
IMS High Performance Load
IMS Online Reorganization Facility (without the ONLINECHANGE(N) option)
IMS Fast Path Advanced Tool of IMS Fast Path Solution Pack

If you use other tools to reorganize the database, before you reload the database, use the INIT.DB command of the LICON utility to manually create an RDE by specifying the updated DBDLIB and the load library that contains the user exit routine as input to the utility. If the IMS management of ACBs is enabled, use the INIT.DB command of the LICON utility to manually create an RDE by specifying the IMS directory.

If you use IMS Online Reorganization Facility with the ONLINECHANGE(N) option to reorganize the database, before you restart the database, use the INIT.DB command of the LICON utility to manually create an RDE by specifying the updated DBDLIB and the load library that contains the user exit routine as input to the utility. If the IMS management of ACBs is enabled and when IMS Online Reorganization Facility is used to reorganize the database, the ONLINECHANGE(N) option is forced. After the IMPORT DEFN SOURCE(CATALOG) command activates the new database definition, use the CHANGE.DB command of the LICON utility to manually re-create the RDE by specifying the IMS directory.

Considerations when reorganizing databases with IMS Database Reorganization Expert

When you reorganize databases to change the DBD definition by using the Smart Reorg utility of IMS Database Reorganization Expert, Integrity Checker creates new RDEs for the changed databases. The following considerations pertain to the maintenance of RDEs.

When Integrity Checker fails to create RDEs

When Integrity Checker fails to create an RDE for a reason such as insufficient space in the LICON data set, it issues error messages. When you receive error messages, to secure the consistency of DMBs, you must confirm whether the RDEs contain the latest DMB information, and, if necessary, create new RDEs.

Check the time stamp of the RDEs.
Run the LIST.DB command of the LICON utility by specifying the reorganized databases as input. From the listing that is generated by the job, check the time stamp to see when the RDE was created. If the time stamp matches the time of the reorganization, the latest RDE was created during the last reorganization.
Ensure that the reorganization of the databases completed successfully.
Examine the messages and reports that are generated by the Smart Reorg utility of IMS Database Reorganization Expert to confirm that the reorganization of the databases completed successfully.
If the databases were reorganized successfully but RDEs are not the latest, create new RDEs.
1. Resolve the cause of the error that occurred while creating new RDEs. For example, by defining a larger LICON data set and copying the data to the new LICON data set.
2. Create new RDEs by using the INIT.DB command of the LICON utility and specifying the updated DBD library and the load library that contains the user exit routine as input. Alternatively, you can create new RDEs by running the reorganization job again.

When you restore the changed databases to their original state

If you decide not to use the reorganized database created with NAMESWAP=NO option or restore the databases and DBD definitions to the original state, you must also restore the RDEs. Run the RECOVER.DB command of the LICON utility.

To restore the RDE, both of the following requirements must be satisfied:

Global option module specifies that historical copies of RDEs are kept (GENMAX=1 or higher).
The RDE that was used before the DBD change is stored in the LICON data set as an expired RDE.

If the expired RDE does not exist, you must use the INIT.DB command of the LICON utility to manually create an RDE that contains the DMB information of the original state.

Considerations when reorganizing databases with IMS Fast Path Advanced Tool of IMS Fast Path Solution Pack

When you reorganize DEDB areas to change the DBD definition by using the Change function or the combination of the Unload and Reload functions, Integrity Checker creates new RDEs for the changed areas. The following considerations pertain to the maintenance of RDEs.

When Integrity Checker fails to create RDEs

Check the time stamp of the RDEs.
Run the LIST.DB command of the LICON utility by specifying the reorganized areas as input. From the listing that is generated by the job, check the time stamp to see when the RDE was created. If the time stamp matches the time of the reorganization, the latest RDE was created during the last reorganization.
Ensure that the reorganization of the areas completed successfully.
Examine the messages and reports that are generated by IMS Fast Path Advanced Tool to confirm that the reorganization of the areas completed successfully.
If the areas were reorganized successfully but RDEs are not the latest, create new RDEs.
1. Resolve the cause of the error that occurred while creating new RDEs. For example, by defining a larger LICON data set and copying the data to the new LICON data set.
2. Create new RDEs by using the INIT.DB command of the LICON utility and specifying the updated ACB library and the load library that contains the user exit routine as input. Alternatively, you can create new RDEs by running the reorganization job again.

When you restore the changed areas to their original state

If you restore the areas and DBD definitions to the original state, you must also restore the RDEs. Run the RECOVER.DB command of the LICON utility.

To restore the RDE, both of the following requirements must be satisfied:

Global option module specifies that historical copies of RDEs are kept (GENMAX=1 or higher).
The RDE that was used before the DBD change is stored in the LICON data set as an expired RDE.

If the expired RDE does not exist, you must use the INIT.DB command of the LICON utility to manually create an RDE that contains the DMB information of the original state.

Considerations when reorganizing databases with IMS Fast Path Basic Tools of IMS Fast Path Solution Pack

When you reorganize a DEDB area to change the DBD definition, Integrity Checker does not create an RDE for the reorganized area. Before you use the reorganized area, you must create an RDE for the area by using the LICON utility.

Considerations when reorganizing databases in the IMS management of ACBs environment

After you reorganize databases to change the DBD definition by using the IMS directory staging data set, you must activate the new database definition by issuing the IMPORT DEFN SOURCE(CATALOG) command. Before you start IMS online, you need to re-create the RDE with the IMS directory by using the LICON utility.