Oracle Bloklayan Oturumları Bulma

SELECT w.sid AS waiting_sid, w.username AS waiting_user,
       w.event, w.seconds_in_wait,
       b.sid AS blocking_sid, b.serial# AS blocking_serial,
       b.username AS blocking_user, b.status AS blocking_status,
       b.sql_id AS blocking_sql_id, b.prev_sql_id
FROM   v$session w
JOIN   v$session b ON b.sid = w.blocking_session
WHERE  w.blocking_session IS NOT NULL
ORDER  BY w.seconds_in_wait DESC;