SYS用户下建立如下TRIGGER， 假设UNIVERSITY用户下的表禁止TRUNCATE：

CREATE OR REPLACE TRIGGER D_T_Trigger
BEFORE TRUNCATE ON DATABASE
begin
if ora_dict_obj_type='TABLE' AND ora_dict_obj_owner='UNIVERSITY' then
Raise_application_error(-20020,'Truncating tables under unservsity schema is not permitted!');
end if;

END ;