Detect oracle cursor leak

 Max open cursors
select name,value from v$parameter where name='open_cursors'; 

Find queries that cause cursor leak
SELECT s.machine, oc.user_name, oc.sql_text, count(1)
FROM v$open_cursor oc, v$session s
WHERE oc.sid = s.sid
GROUP BY user_name, sql_text, machine
HAVING COUNT(1) > 2
ORDER BY count(1) DESC
;