Important:

This feature applies only to child base objects with configured match rules and foreign keys.

For child base objects,

Informatica MDM Hub

provides a

cascade unmerge

feature that allows you to specify what happens if records in the parent base object are unmerged. By default, this feature is disabled, so that unmerging parent records does not unmerge associated child records. In the Unmerge Child When Parent Unmerges portion near the bottom of the Merge Settings tab, if you check (select) the Cascade Unmerge check box for a child base object, when records in the parent object are unmerged,

Informatica MDM Hub

also unmerges affected records in the child base object.