Sometimes RMAN job take long time and need to kill job to investigate problem, below script show you how to kill job.
SQL>SELECT p.SPID, s.sid, s.serial#, sw.EVENT, sw.SECONDS_IN_WAIT AS SEC_WAIT, sw.STATE, CLIENT_INFO
FROM V$SESSION_WAIT sw, V$SESSION s, V$PROCESS p
WHERE s.client_info LIKE 'rman%'
AND s.SID=sw.SID
AND s.PADDR=p.ADDR;
When you found necessary data you should use below script to kill job
SQL> alter system kill session '683, 43845';
SQL>SELECT p.SPID, s.sid, s.serial#, sw.EVENT, sw.SECONDS_IN_WAIT AS SEC_WAIT, sw.STATE, CLIENT_INFO
FROM V$SESSION_WAIT sw, V$SESSION s, V$PROCESS p
WHERE s.client_info LIKE 'rman%'
AND s.SID=sw.SID
AND s.PADDR=p.ADDR;
When you found necessary data you should use below script to kill job
SQL> alter system kill session '683, 43845';