Trigger for blocking user using third party tool !

Question

Dear Friends ,
I have to block the users from using sqlplus, TOAD, PLsldev etc (Except SYSTEM user) from client end using the below trigger :
create or replace trigger check_logon
after logon on database
declare
cursor c_check is
select
sys_context('userenv','session_user')
username,
s.module,
s.program
from v$session s
where
sys_context('userenv','sessionid')=s.audsid;
lv_check c_check%rowtype;
begin
open c_check;
fetch c_check into lv_check;
if lv_check.username in ('SYSTEM')
then
null;
elsif upper(lv_check.module) like
('%SQL*PLUS%') or
upper(lv_check.program) like
('%SQLPLUS%')  or
upper(lv_check.module) like
('%T.O.A.D%') or
upper(lv_check.program) like
('%TOAD%')    or
upper(lv_check.program) like
('%PLSQLDEV%')    or
upper(lv_check.program) like
('%BUSOBJ%')    or
upper(lv_check.program) like
('%EXCEL%')
then
close c_check;
raise_application_error(-
20100,'Banned! Contact with Database Admin!');
end if;
close c_check;
end;
It works fine all normal user cannot access the database using above third party tools .
But the problem is , user with DBA privileges can access the database with generating an trace file . Is there any way to restrict DBA Privileged user ? or is there any mechanism to create a log/trace file so that If there any  DBA Privilege user acess to the Database , then we can get the information from that specified log/trace file ? 
Waiting your kind reply ... ...

Answer 1

Hi,
If the DBA users has the DBA role granted to them so they will by passes the logon trigger. For example, the SYSTEM user has the DBA role and the DBA role has the ADMINISTER DATABASE TRIGGER privilege. The ADMINISTER DATABASE TRIGGER by pass the logon trigger. If you want to restrict the access to a DBA user, then you need to revoke the ADMINISTER DATABASE TRIGGER privilege from the DBA role or grant individual privileges except the ADMINISTER DATABASE TRIGGER privilege to the DBA users.
Cheers
Legatti