Overview—multiple database reorganization

The benefits of copying and reorganizing multiple databases in one job step include:

• Reorganizing and copying all logically related databases
• Reorganizing and copying all databases in an application group
• Reducing log switches

The following figure shows the task flow of an online reorganization job for a multiple database reorganization. Refer to the text explanation that follows.

The following steps describe the multiple database reorganization process for the Online/Reorg function:

1. Preprocessing
   /BMCPAU is issued to quiesce the databases. Log recording is initiated. /STA is issued to start the databases and release any suspended transactions.
2. Copy
   Each database is assigned to a separate unit of work (UOW) and copied.
3. Post copy
   /BMCPAU is issued to quiesce the databases. Log recording is terminated. Logs are applied. Change recording is initiated. /STA is issued to start the databases and release any suspended transactions.
4. Reorg
   Each database is assigned to a separate UOW and reorganized.
5. Post processing
   Prefix resolution and updates are performed. /DBR is issued to stop the databases. Changes are applied. Change recording is terminated. /STA is issued to start databases. Data sets are swapped. DBRC functions are performed. You can run only one restart job. You can include the name of any one of the databases from the GROUP subcommand for the PARM keyword, but only one restart job should be run. Restart automatically runs for all of the databases.