Oracle Level 12 tracing

We can enable level 12 tracing by
exec sys.dbms_system.set_ev(&sid, &serial, 10046, 12, '')

and then stop it with
exec sys.dbms_system.set_ev(&sid, &serial, 10046, 0, '')

Normal level tracing
execute sys.dbms_system.set_sql_trace_in_session (&sid,&serial,true);