Add ExternalSystem table FK from external_sys.created_by to usr.id. FK from external_sys.updated_by to usr.id. Create role map table for external_sys. Add PK for external_sys_rm. Add FK from external_sys_rm to rm_entry.id. Add FK from external_sys_rm to external_sys.id. Create an index for the FK column external_sys_rm.rm_entry_id Add a system role (in rm_role) for External System Administrator. Add a system role (in rm_role) for External System Editor. Add a system role (in rm_role) for External System Auditor. Add a system role (in rm_role) for External System Viewer.