Disable DDL statements using system-level triggers in Oracle

DDL operations are very cautious when running a system online. To prevent unnecessary misoperation, you can use DDL triggers to disable DDL operations on some tables. You can use the raise_application_error function to disable the operation on the operation type to be disabled. For example:

Create or replace trigger DDL_FB before ALTER OR DROP OR RENAME

On schema

BEGIN

Raise_application_error (-20030, 'this system is running and cannot perform DDL maintenance on the table ');

End;

If you need to modify the table structure of a user who has set such a trigger, you must first turn off the trigger.