select event,count(*) from gv$session_wait group by event order by count(*) desc;

 

SELECT s.sid,s.serial#,p.spid, t.sql_text FROM v$session s, v$sql t, v$process p
WHERE s.event LIKE 'row cache lock' AND t.sql_id = s.sql_id AND s.PADDR = p.ADDR ;

Alter system kill session 'SID,SERIAL#'  ;