ORA-30013: Undo Tablespace ‘UNDOTBS1’ Is Currently In Use

You might get this error, when you tried to drop the undo table. Its because , there are some active transactions in the undo. The solution is to find that transaction and kill the same.

set pagesize 200 

set lines 200 

set long 999 col username for a9 

SQL>SELECT a.name,b.status , d.username , d.sid , d.serial# FROM v$rollname a,v$rollstat b, v$transaction c , v$session d WHERE a.usn = b.usn AND a.usn = c.xidusn AND c.ses_addr = d.saddr AND a.name IN ( SELECT segment_name FROM dba_segments WHERE tablespace_name = 'UNDOTBS1' );

NAME STATUS USERNAME SID SERIAL# 

---------- --------------- ----------- ---------- ---------- 

_SYSSMU691$ PENDING OFFLINE SCOTT 20 30

Now kill this sessions:

alter system kill session '20,30' immediate; 

system altered

The KILL SESSION command doesn't actually kill the session. It merely asks the session to kill itself. In some situations, like waiting for a reply from a remote database or rolling back transactions, the session will not kill itself immediately and will wait for the current operation to complete. In these cases the session will have a status of "marked for kill". It will then be killed as soon as possible.

Check the status to confirm:

SELECT sid, serial#, status, username FROM v$session;

You could also use IMMEDIATE clause:

ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;

The IMMEDIATE clause does not affect the work performed by the command, but it returns control back to the current session immediately, rather than waiting for confirmation of the kill. Have a look at Killing Oracle Sessions.

Update If you want to kill all the sessions, you could just prepare a small script.

SELECT 'ALTER SYSTEM KILL SESSION '''||sid||','||serial#||''' IMMEDIATE;' FROM v$session;

OR in one go

BEGIN
  FOR r IN (select sid,serial# from v$session where username='user')
  LOOP
      EXECUTE IMMEDIATE 'alter system kill session ''' || r.sid  || ',' 
        || r.serial# || ''' immediate';
  END LOOP;
END;

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