TIMEOUT OCCURED WHILE CREATING TRIGGER

Post the trigger code.
Are you using a "pragma autonomous_transaction" ?

GURU -->
I am using the following trigger
create or replace trigger vch_det before update or delete or insert on voucher_detail for each row
declare
---
begin
  if inserting then
   ----
  end if
end;

When i restart my database i am able to run above script, but there is one constraint that i am working online therefore i cannot restart database every times.  i want to know which user has locked the table other than me. also when i kill all the users belong to finance user using entreprise console, i am able to recompile OR create the trigger.

Try:
 SELECT * FROM v$session WHERE sid IN (SELECT sid FROM v$access WHERE TYPE='TABLE' AND OBJECT='VOUCHER_DETAIL')
to determine other sessions accessing the table and investigate them further.

adrian_ang:,,,,sujith80:,,
after running the following query i have killed all the sesions dispalyed by this query.
SELECT * FROM v$session WHERE sid IN (SELECT sid FROM v$access WHERE TYPE='TABLE' AND OBJECT='VOUCHER_DETAIL')

but still  i m facing the same problem of timeout occur while trying to lock the object

Yes that will continue to happen.
Because, ideally you are not supposed to have active transactions on the table on which you are creating the trigger. That is the reason why it tries to acquire a lock. You cannot get rid of that.
Now, you have active sessions on the object. Only thing you can do is, perform the trigger creations during a downtime. On weekends or something.

Ok, But when i came next day i again run create trigger, which works fine. One thing more, before closing the department i had killed all the active session which was using that tables.. I am not sure whether i am right or not, i thing oracle had not unlocked the resources after kill the session till i again fire create trigger.
On that day i was repeadly killing some of the uses session and re-creating the trigger, i didn't find any problem.
Today i am facing new problem, I want to alter system_parameter table, same error message is reflected back. By using the query from v$session and v$access, no record found. Also I am using SQL PLUS on Application Server. Pls help what is the cauise

It is observed that when i opened the form referencing the table in developer 2000, that table is locked for alter, drop etc. the views v$locked_object and v$access is not showing the lock information. Why?