Syntax Specify the name of the trigger to be created.
Therefore, you should not write triggers intended to affect the content of the materialized view. In other words, the database fires the triggers instead of performing DML on the view.
Like a stored procedure, a trigger is a named PL/SQL unit that is stored in the database and can be invoked repeatedly.
Constraint behavior depends on constraint state, as explained in .
Constraints are easier to write and less error-prone than triggers that enforce the same rules.