Migrate Model from One Model to Another › Understanding Migration

Understanding Migration

Migration copies an aggregate object and its related components from one member of a model family to another model of the same family.

To do this, migration checks source and destination models to determine whether the aggregate object being migrated exists in both models. Objects that exist in both models either have common ancestry or conform to the special cases for that object type.

Note: For more information about expansions and special cases, see Aggregate Object Expansions in the Migration Rules appendix. For information about how to create common ancestry, see the Perform Trial Adoption and Adoption section in the Perform Adoption or Unadoption chapter. For information about removing common ancestry, see Perform Model Unadoption in the Perform Adoption or Unadoption chapter.

If the aggregate object being migrated exists in both source and destination models and has common ancestry, the migration process:

• Deletes the aggregate object and its components from the destination model
• Copies the aggregate object and its components from the source model into the destination model
• Validates the destination model to ensure that it is left in a valid state

Important! There is no command to back out a migration that has unforeseen consequences. Keep the backups of the destination models because migration changes cannot be easily undone.