SQL & PL/SQL :: Enabling Constraint With Enable No Validate?

Is there any way to enable the constraint with out validating for the existing information.

As We can accomplish the same functionality when we are adding the constraint for the first time.

Ex: alter table scott.emp add constraint fk_deptno foreign key(deptno) references scott.dept(deptno) enable novalidate

The above SQL statement will enable the constraint with out validating for the existing information. So there is possibility of data will be there only in the child table but not in the parent table for existing information.

But in the future it will not allow to do so,if the constraint is in ENABLE staus.So i am just trying to disable the constraint to insert only into child table & trying to enable it with NOVALIDATE option .

But the following exception is coming .

SQL> alter table scott.emp ENABLE constraint fk_deptno enable NOVALIDATE;

alter table scott.emp ENABLE constraint fk_deptno enable NOVALIDATE

ORA-00905: missing keyword

SQL> alter table scott.emp ENABLE constraint fk_deptno NOVALIDATE;

alter table scott.emp ENABLE constraint fk_deptno NOVALIDATE

ORA-00933: SQL command not properly ended

Instead of dropping & recreating the same constraint , is there any alternate way to do this ?