Online change performance considerations

Deleting databases from the IMS™.MODBLKS data set using Online Change incurs the performance overhead of reading the intent lists from the ACB library for all application programs in MODBLKS whose intent lists are not loaded.

This is necessary to determine which transactions need to stop queuing, to prevent work that might cause commit to fail. This performance overhead is proportional to the number of application programs defined in MODBLKS for which the intent list is not loaded.

Recommendation: If you need to delete databases from MODBLKS, consider performing an IMS cold start instead of using local or global online change.
Parent topic: Overview of the local online change function