ORA-02021: DDL operations are not allowed on a remote database

*Cause: An attempt was made to use a DDL operation on a remote database.
 For example, “CREATE TABLE tablename@remotedbname …”.
*Action: To alter the remote database structure, you must connect to the
remote database with the appropriate privileges.

But you can avoide this  Using :

exec dbms_utility.exec_ddl_statement@db_link(‘your statment’);

Thank you
Osama Mustafa