How to detect and kill long running processes in Oracle

To get a list of long running processes/sessions:

SELECT sid,opname,sofar,totalwork,units,elapsed_seconds,time_remaining

FROM v$session_longops

 --WHERE sofar != totalwork;

 orderby ELAPSED_SECONDS DESC

To view all sessions:

select *
from  v$session s
orderbysid;

To kill a session:

ALTER SYSTEM KILL SESSION 'sid,serial#';

 (where sid and serial no are taken from the data shown in the script above.