script to find most CPU consuming oracle database session

select a.username,a.logon_time,b.SQL_FULLTEXT from v$session a,v$sqlarea b where
a.sql_id=b.sql_id
and a.username='&USER'
order by a.logon_time desc;
SELECT CPU,Total_Rows,sql_text FROM(
SELECT (s.cpu_time/1000000) CPU, sa.rows_processed Total_Rows, SUBSTR(sa.sql_text,1,50) sql_text
FROM v$sqlarea sa, v$sql s
WHERE sa.parsing_user_id =
(SELECT user_id FROM dba_users WHERE username='USER'
AND s.sql_text = sa.sql_text)
ORDER BY s.cpu_time DESC)
WHERE ROWNUM <= 10;