V$LOCKED_OBJECTを使うとロックしているテーブルを調べることができる
SELECT V$SESSION.SID, DBA_OBJECTS.OBJECT_NAME, V$SESSION.OSUSER, V$SESSION.PROGRAM, V$SESSION.MACHINE , V$SESSION.CLIENT_IDENTIFIER FROM V$LOCKED_OBJECT LEFT JOIN DBA_OBJECTS ON V$LOCKED_OBJECT.OBJECT_ID = DBA_OBJECTS.OBJECT_ID LEFT JOIN V$SESSION ON V$LOCKED_OBJECT.SESSION_ID = V$SESSION.SID ORDER BY V$SESSION.SID, DBA_OBJECTS.OBJECT_NAME
動作確認環境:oracle 11g