How to check long running queries in oracle databasE?

select substr(username,1,15),target,to_char(start_time, 'DD-Mon-YYYY HH24:MI:SS' ), SOFAR,substr(MESSAGE,1,70) from v$session_longops;


select USERNAME, to_char(start_time, 'DD-Mon-YYYY HH24:MI:SS' ),substr(message,1,90),to_char(time_remaining) from v$session_longops;