SELECT a.osuser,
a.sid,
b.os_user_name,
b.oracle_username,
b.session_id,
c.object_name,
c.object_type
FROM v$session a, v$locked_object b, dba_objects c
WHERE a.sid = b.session_id
AND b.object_id = c.object_id
AND c.object_name = UPPER ('TABLE_NAME');