Remigrating to Db2 12

Remigrating (returning to Db2 12 after falling back to Db2 11) is simpler than the initial migration process.

Before you begin

Before you remigrate, refer to Incompatible changes in Db2 12 because many of those considerations apply to remigration, too. Whether each consideration applies to your subsystem depends on the type of activity that took place on your Db2 11 subsystem after falling back.

Start of changeRegardless of the ABIND subsystem parameter value, plans and packages continue to run on Db2 12 as bound on Db2 11, until you explicitly rebind them on Db2 12. It is best to do so only after you are certain that Db2 12 is stable and release coexistence and fallback are no longer a concern.End of change

Recommendation: Avoid automatic rebinds during migration and remigration. After your remigrated system is stable, you can rebind your packages with PLANMGMT(EXTENDED). If a new package does not perform adequately, you can rebind with SWITCH(PREVIOUS) to return to the old package.

Procedure

To remigrate your subsystem to Db2 12:

  1. Check the integrity of your Db2 11 catalog and directory:
    • Run the DSN1COPY utility with the CHECK option on your catalog table spaces.
    • Run the CHECK DATA utility.
    • Run the queries in member DSNTESQ of prefix.SDSNSAMP.
  2. Optional: Ensure that your Db2 11 DSNTIJIC job has been modified to copy new Db2 12 catalog table spaces, and then use DSNTIJIC to take an image copy of your Db2 11 catalog.
    This step is not required, but it is recommended.
  3. Stop Db2 11.
  4. Reconnect TSO, IMS, and CICS® to Db2.
    Re-establish your Db2 12 logon procedures and JCL, as well as your Db2 12 CICS and IMS connections.
  5. Rebuild Db2 12 cataloged procedures.
    Rename the Db2 12 procedures that were renamed by job DSNTIJFV during fallback. If job DSNTIJFV was not run, you need to rerun job DSNTIJMV. Comment out step 1 (DSNTIMP), which defines Db2 12 to z/OS®, and run the job. (You do not need to define Db2 12 to z/OS a second time.)
  6. Start Db2 12. Ensure that you are using your Db2 12 subsystem parameter load module.
  7. Take an image copy of the Db2 12 catalog by using the DSNTIJIC job.
  8. Verify your Db2 12 system.