dba_locks does not show for both instances

Problem: While working on blocking session script below, I figured out that blocking sessions are not displayed in both nodes of the rac, exadata.

SELECT
 decode (s2.sid,s1.FINAL_BLOCKING_SESSION,'*'||s2.sid,' '||s2.sid) Blocker_SID
 ,s2.serial# blocker_serial
 ,s2.inst_id blocker_inst_id
 ,s2.con_id Blocker_con_id
 ,s2.status Blocker_Status
 ,s2.username Blocker_User
 ,s2.osuser Blocker_OS_User
 ,s2.process Blocker_OS_PID
 ,s2.sql_id Blocked_sql_id
 ,o.owner Object_owner
 ,o.object_name Locked_Object
 ,o.object_type Locked_Object_Type
 ,l2.lock_type Blocking_Lock_Type
 ,substr(s2.program,1,10) Blocker_Program
 ,s2.client_info Blocker_Client
 ,s1.sid blocked_sid
 ,s1.inst_id blocked_inst_id
 ,s1.con_id Blocker_con_id
 ,s1.status Blocked_Status
 ,s1.username Blocked_User
 ,s1.osuser Blocked_OS_User
 ,s1.process Blocked_OS_PID
 ,s1.sql_id Blocked_sql_id
 ,s1.last_call_et Blocked_Age
 ,substr(s1.program,1,10) Blocked_Program
 ,s1.client_info Blocked_Client
 FROM gv$session s2
 join gv$session s1 ON (s1.blocking_session=s2.sid)
 join dba_objects o on (o.object_id=s1.ROW_WAIT_OBJ#)
 join dba_locks l2 on (s2.sid=l2.session_id)
 left join dba_locks l1 on (s1.sid=l1.session_id and l1.lock_type = l2.lock_type AND l1.lock_id1 = l2.lock_id1 AND l1.lock_id2 = l2.lock_id2)
 where s1.last_call_et>10 and upper(l2.MODE_HELD)='EXCLUSIVE';

Cause: Usual suspect in the from clause are dba_objects, gv$session, and dba_locks. I just look into the dba_locks, because dba_objects is just related with database physical structure which should be common in RAC. gv$session also cannot be, because it is gv$, it must surely include common information among instances again. So, it must be for dba_locks, and there it is,

desc DBA_LOCKS
SESSION_ID NUMBER
LOCK_TYPE VARCHAR2(26)
MODE_HELD VARCHAR2(40)
MODE_REQUESTED VARCHAR2(40)
LOCK_ID1 VARCHAR2(40)
LOCK_ID2 VARCHAR2(40)
LAST_CONVERT NUMBER
BLOCKING_OTHERS VARCHAR2(40)

Solution:

There must be alternative real RAC aware version of it. It is GV$LOCK, some small differences in column names, and values, it has same information, and it shows more for both nodes.

desc GV$LOCK
INST_ID NUMBER
ADDR RAW(8)
KADDR RAW(8)
SID NUMBER
TYPE VARCHAR2(2)
ID1 NUMBER
ID2 NUMBER
LMODE NUMBER
REQUEST NUMBER
CTIME NUMBER
BLOCK NUMBER
CON_ID

Before my script looks like this:

SELECT
 decode (s2.sid,s1.FINAL_BLOCKING_SESSION,'*'||s2.sid,' '||s2.sid) Blocker_SID
 ,s2.serial# blocker_serial
 ,s2.inst_id blocker_inst_id
 ,s2.con_id Blocker_con_id
 ,s2.status Blocker_Status
 ,s2.username Blocker_User
 ,s2.osuser Blocker_OS_User
 ,s2.process Blocker_OS_PID
 ,s2.sql_id Blocked_sql_id
 ,o.owner Object_owner
 ,o.object_name Locked_Object
 ,o.object_type Locked_Object_Type
 ,l2.lock_type Blocking_Lock_Type
 ,substr(s2.program,1,10) Blocker_Program
 ,s2.client_info Blocker_Client
 ,s1.sid blocked_sid
 ,s1.inst_id blocked_inst_id
 ,s1.con_id Blocker_con_id
 ,s1.status Blocked_Status
 ,s1.username Blocked_User
 ,s1.osuser Blocked_OS_User
 ,s1.process Blocked_OS_PID
 ,s1.sql_id Blocked_sql_id
 ,s1.last_call_et Blocked_Age
 ,substr(s1.program,1,10) Blocked_Program
 ,s1.client_info Blocked_Client
 FROM gv$session s2
 join gv$session s1 ON (s1.blocking_session=s2.sid)
 join dba_objects o on (o.object_id=s1.ROW_WAIT_OBJ#)
 join dba_locks l2 on (s2.sid=l2.session_id)
 left join dba_locks l1 on (s1.sid=l1.session_id and l1.lock_type = l2.lock_type AND l1.lock_id1 = l2.lock_id1 AND l1.lock_id2 = l2.lock_id2)
 where s1.last_call_et>10 and upper(l2.MODE_HELD)='EXCLUSIVE';

After making modifications on column names and, associated values, my script turns out to be as follows:

SELECT
 decode (s2.sid,s1.FINAL_BLOCKING_SESSION,'*'||s2.sid,' '||s2.sid) Blocker_SID
 ,s2.serial# blocker_serial
 ,s2.inst_id blocker_inst_id
 ,s2.con_id Blocker_con_id
 ,s2.status Blocker_Status
 ,s2.username Blocker_User
 ,s2.osuser Blocker_OS_User
 ,s2.process Blocker_OS_PID
 ,s2.sql_id Blocked_sql_id
 ,o.owner Object_owner
 ,o.object_name Locked_Object
 ,o.object_type Locked_Object_Type
 ,l2.type Blocking_Lock_Type
 ,substr(s2.program,1,10) Blocker_Program
 ,s2.client_info Blocker_Client
 ,s1.sid blocked_sid
 ,s1.inst_id blocked_inst_id
 ,s1.con_id Blocker_con_id
 ,s1.status Blocked_Status
 ,s1.username Blocked_User
 ,s1.osuser Blocked_OS_User
 ,s1.process Blocked_OS_PID
 ,s1.sql_id Blocked_sql_id
 ,s1.last_call_et Blocked_Age
 ,substr(s1.program,1,10) Blocked_Program
 ,s1.client_info Blocked_Client
 FROM gv$session s2
 join gv$session s1 ON (s1.blocking_session=s2.sid)
 join dba_objects o on (o.object_id=s1.ROW_WAIT_OBJ#)
 join gv$lock l2 on (s2.sid=l2.sid)
 left join gv$lock l1 on (s1.sid=l1.sid and l1.type = l2.type AND l1.id1 = l2.id1 AND l1.id2 = l2.id2)
 where s1.last_call_et>10 and l2.LMODE=6;