For pre-packaged applications, constraint definition is required only if you have custom tables or if you modified standard application tables. Constraints for standard application tables are included in the application accelerators. When you install the accelerators, the metadata and the constraints are imported to the ILM repository.

For custom applications, constraint definition depends on how the source database stores constraints. If the source database maintains constraints at the database level, the constraints are automatically created in the ILM repository when you import metadata from the source database. If the source database maintains constraints other than at the database level, such as in the application logic, you must define the constraints. You must define constraints if constraint information is not included when you import metadata from the source application.

For SAP applications, constraint definition is required. When you import metadata from SAP applications, only contraints that are defined at the database level are imported. Constraints that are defined in the SAP ABAP Dictionary are not imported. Constraints are not required to retire the SAP application. Constraints are required to create entities for Data Discovery portal searches. You may want to define the constraints after you retire the application.