Alter the constraints on a view using ALTER VIEW

ALTER VIEW your_view_name
DROP CONSTRAINT view_constraint_name;

1. Creating and Using a View
2. Creating and Using Simple Views
3. Performing an INSERT Using a View
4. A View with a CHECK OPTION Constraint
5. View with a READ ONLY Constraint
6. Getting Information on View Definitions with DESCRIBE command
7. Getting Information on View Definitions with user_views view
8. Retrieving Information on View Constraints
9. Creating and Using Complex Views
10. Modifying a View
11. Alter the constraints on a view using ALTER VIEW
12. Dropping a View