Using OEM 13c data masking pack.
Can relationship be defined across multiple databases when creating application data model?
E.g. scenario –
Database_A (source), table_a, column_a is related to Database_B, table_b, column_b.

Desired outcome:
When database_a.table_a.column_a is masked, the same masking should also get applied to
database_b.table_b.column_b automatically.

What I tried –
I can add user-defined relationship between columns within same application and same schema;
however, it does not works when trying to use multiple database or schema.

What is being done –
Multiple application defined in ADM that maps to different databases.

Created an ADM and associated two databases with the ADM.
Edit Application Data Model
Go to Tab “Referential Relationship” and Click Add
Enter application (app_a mapped to database_a) and the object (table_a), under parent key on the left side.
Enter application (app_b mapped to database_b) and object (table_b), under Dependent key on right side.
Click on columns “+” icon under the parent key (left side)
It pops-up following error –
“The application and object for both the parent key and the dependent key must be selected before adding key columns.”