Running a delta data (incremental) migration job

An incremental (or delta) data migration is a special kind of data migration that is intended only to migrate data that has been changed in the source system since a selected date and time. Typically, the target system will already have been populated with the data which was changed prior to the selected date and time. The aim of a delta data migration is to fully synchronize two BMC Helix ITSM systems.

Filtering the data in this way is intended to reduce the overall migration time and is useful as part of an upgrade project where the final cutover data migration is time critical.

For an incremental data migration to be successful, it must replicate record creations and modifications but also data deletions. BMC Helix Data Manager fully supports all aspects of incremental data migration.

To perform an incremental data migration

1. Create a new migration job and select an export template with the Incremental Export setting.
2. Run the export job.
3. Create and run the import job with an import template that supports incremental import.
   Select the Form Deletion template appropriate for your migration. Form deletion checking is an expensive operation, and the Form Deletion template allows you to restrict the deletion checking appropriate for your change freeze and application usage.

Incremental data migration will be successful only if you have migrated the baseline data previously and have followed the best practices for data management.  Contact BMC Support for details on how to effectively manage your data migration scenarios.

To check for deleted forms

When performing an incremental data migration, you can configure BMC Helix Data Manager to check for record deletions across a range of selected forms. This list of forms is typically configured to include those in which record deletions occur as part of everyday usage of the BMC Helix ITSM application. You can extend this list to include custom forms or other forms where records are deleted manually or through custom workflow.

Changes to the list of forms checked for deletions take place immediately and will be picked up the next time an import job is run. This allows changes to be made to suit your business objectives.

To view the Form Deletion page, select Configuration > Form Deletion from the navigation bar.