Running the Online Structure Change utility

To restructure an online DEDB with the Online Structure Change utility, complete the following steps.

Before you begin

Before you can run the Online Structure Change utility, you must ensure that your environment is ready to run an OSC job:

  • Ensure that the Online Structure Change utility environment is configured correctly. For configuration steps, see the topic "Setting up the Online Structure Change utility" in IMS Fast Path Solution Pack: Overview and Customization.
  • Ensure that, for each ADS, the number of copies is less than seven. For more information, see Multiple area data set (MADS).
  • Ensure that all IMS systems in the IMSplex where you run the OSC job have the executable load library of IMS HP Fast Path Utilities (SHFPLMD0) in the STEPLIB concatenation.
  • If you want to replace the randomizer or segment edit/compression exit routines, ensure that the randomizer or the segment edit/compression exit routines are not being used by other databases.
Tip: If you want to change default values of the utility control statements, create a site default table. For more information, see Setting site default values for the Online Structure Change utility.

Procedure

  1. Create an OSC driver job.
  2. Optional: Estimate the region size that is required to run the job. For more information, see Region size requirements for the Online Structure Change utility.
  3. Code DD statements to define input and output data sets.

    For a list of DD statements, see JCL requirements for the Online Structure Change utility.

    • If you created a base configuration module, you must add the module to the STEPLIB concatenation.
    • If you created a site default table, you must add the library that contains the site default member (HFPOCTL0) to the STEPLIB or JOBLIB concatenation.
  4. Code the utility control statements for the HFPSYSIN DD statement.

    For a list of control statement keywords, see Utility control statements for the Online Structure Change utility. GLOBAL command, RESTRUCTURE command, ALLOCATE subcommand, and JCLPARM subcommand are required. LOADCTL subcommand is optional.

    The following sub-steps describe keywords that require allocation of data sets:

    1. Define and allocate an OSC internal jobs data set. If the data set exists, ensure that it has enough space. Specify this data set for the JCLDSN keyword of the JCLPARM subcommand.

      The Online Structure Change utility generates OSC internal jobs in this data set.

      • This data set, if used by multiple OSC driver jobs, must be a PDSE.
      • The name of the data set must match the SDN parameter that is specified in the internal reader facility procedure.
    2. Define and allocate an OSC internal job log data set. If the data set exists, ensure that it has enough space. Specify the prefix of this data set for the LOGDSN keyword of the JCLPARM subcommand.

      The Online Structure Change utility stores job logs from the OSC internal jobs in this data set.

      Tip: If the OSC driver job ends abnormally, you can submit the xxxxxxG0 job (generated by the OSC driver job) to collect all the job logs in this data set.
    3. Create a partitioned data set and code IDCAMS control statements for each area. Specify these data sets to the ATTRIBUTE keyword of the ALLOCATE subcommand.

      For each area, you must create a member that contains IDCAMS control statements for allocating the restructured area. For more information, see Example: Specifying the ALLOCATE subcommand.

    4. Define and allocate an ENQ data set. The Online Structure Change utility uses this data set in the online change process. If the data set exists, ensure that it has enough space. Specify this data set for the ENQDSN keyword of the JCLPARM subcommand.

      The Online Structure Change utility generates some internal SYSIN files in the ENQ data set. For more information about SYSIN files generated in ENQ data sets, see Internal SYSIN files.

      • This data set, if used by multiple OSC driver jobs, must be a PDSE.
      • If you plan to execute multiple OSC driver jobs simultaneously in an IMSplex, all the SYSIN files must be generated in one ENQ data set. Ensure that the ENQDSN keywords in all OSC driver jobs specify the same ENQ data set.
      • The name of the ENQ data set must not be the same as the name of the OSC internal jobs data set.
    For the following keyword values, consult your system administrators for the values they used to configure the Online Structure Change utility environment:
    CONFIGLIB_DSN keyword (JCLPARM subcommand)
    Specify the base configuration module.
    INTRDR keyword (JCLPARM subcommand)
    Specify the internal reader facility procedure.
    TOIXCFGRP keyword (GLOBAL command)
    Specify the XCFGROUP name that the IMS Tools Online System Interface uses in the production IMS systems.
    TOIXCFGRP_APPLY keyword (JCLPARM subcommand)
    Specify the XCF group name that the IMS Tools Online System Interface uses in the IMS DBCTL system.
  5. Optional: Supply the ERRORACT keyword. The ERRORACT keyword enables you to specify the action for the utility to take when one of the OSC internal job fails. This keyword helps you troubleshoot Online Structure Change utility problems.

    If you specify ERRORACT=WTOR, the utility issues WTOR message HFPT0512A to prompt you to select the next action to take. If you specify ERRORACT=ABEND, the OSC driver job terminates when one of the OSC internal jobs fails.

  6. If you specify ORIGADS_PROC=RENAME to rename the original ADSs, delete or rename the VSAM data set whose name is original_ADS_name + .T.
  7. Ensure that the DEDB is registered to the IMS DBCTL system and that the IMS DBCTL system is started with the new ACB definition.
  8. Activate the OSC logger exit routine.
    The OSC logger exit routine is activated when the IMS control region is started. Ensure that the following messages are issued: 
    HFP01000I LOGGER EXIT INITIALIZING 
HFP01503I JOINED XCF GROUP xxxxxxxx AS MEMBER yyyy
HFP01000I LOGGER EXIT INITIALIZED
  9. Submit the OSC driver job.

    Ensure that the job ends without errors. If you receive error messages, look up the messages in Troubleshooting. Also, see Troubleshooting Online Structure Change utility problems .

    If an OSC internal job ends with a JCL error, cancel the OSC driver job. Review the JCL for the OSC driver job, specify the correct job statements using the JOBCARDx keywords, and rerun the OSC driver job.

  10. Stop the IMS DBCTL system.