Actions to avoid in recovery of inconsistent data

To minimize problems when recovering inconsistent data, you can avoid doing certain actions.

• Do not discard archive logs that you might need.

  The RECOVER utility might need an archive log to recover from an inconsistent data problem. If you have discarded it, you cannot use the RECOVER utility and must resolve the problem manually.

• Do not make an image copy of a page set that contains inconsistent data.

  If you use the COPY utility to make an image copy of a page set that contains inconsistent data, the RECOVER utility cannot recover a problem that involves that page set unless you have an older image copy of that page set that was taken before the problem occurred. You can run DSN1COPY with the CHECK option to determine whether intra-page data inconsistency problems exist on page sets before making image copies of them. You can also specify the CHECKPAGE parameter on the COPY utility which will cause the image copy to fail if an inconsistent page is detected.

• Do not use the TERM UTILITY command on utility jobs that you want to restart.

  If an error occurs while a utility is running, the data on which the utility was operating might continue to be written beyond the commit point. If the utility is restarted later, processing resumes at the commit point or at the beginning of the current phase, depending on the restart parameter that was specified. If the utility stops while it has exclusive access to data, other applications cannot access that data. In this case, you might want to issue the TERM UTILITY command to terminate the utility and make the data available to other applications. However, use the TERM UTILITY command only if you cannot restart or do not need to restart the utility job.

  When you issue the TERM UTILITY command, two different situations can occur:

  • If the utility is active, it terminates at its next commit point.
  • If the utility is stopped, it terminates immediately.

  If you use the TERM UTILITY command to terminate a utility, the objects on which the utility was operating are left in an indeterminate state. Often, the same utility job cannot be rerun. The specific considerations vary for each utility, depending on the phase in process when you issue the command.