Find on which row is waiting blocked sesssion when you have TX - row lock contention

There may be situation When your session is Waiting for row lock, but which row is locked in oracle database?
Here I'll show you how to find on which row is waiting blocked session in Oracle Database when you have row level lock (enq: TX - row lock contention).
Let's Demonstrate small demo
Session 1

SQL> select * from scott.dept;
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
    20 RESEARCH       DALLAS
    30 SALES          CHICAGO
    40 OPERATIONS     BOSTON

SQL> update scott.dept set loc='SESSION1' where deptno=10; 
 
1 row updated

Session 2

SQL> select * from scott.dept;
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
    20 RESEARCH       DALLAS
    30 SALES          CHICAGO
    40 OPERATIONS     BOSTON

SQL> update scott.dept set loc='SESSION2' where deptno=10; 

Now second session waiting for first session because there is row lock on table scott.dept and we need to find on which row is waiting second session

SQL> select sid, event from gv$session where event like 'enq%';
 
       SID EVENT
---------- ----------------------------------------------------------------
       133 enq: TX - row lock contention
 
SQL> column owner format a10
SQL> column object_name format a12
SQL> column row_wait_obj# format a10
SQL> column row_wait_file# format a6
SQL> column row_wait_block# format a8
SQL> select o.owner,
           o.object_name,
           row_wait_obj#,
           row_wait_file#,
           row_wait_block#,
           row_wait_row#,
           dbms_rowid.rowid_create(1,
                                   o.DATA_OBJECT_ID,
                                   ROW_WAIT_FILE#,
                                  ROW_WAIT_BLOCK#,
                                  ROW_WAIT_ROW#) as "RowID"
     from gv$session s, 
          dba_objects o
     where sid = 133    ---- waiting session id
     and s.ROW_WAIT_OBJ# = o.OBJECT_ID;
 
OWNER      OBJECT_NAME  ROW_WAIT_O ROW_WA ROW_WAIT ROW_WAIT_ROW# RowID
---------- ------------ ---------- ------ -------- ------------- ------------------
SCOTT      DEPT              75333      4      135             0 AAASZFAAEAAAACHAAA
 
SQL> select * from scott.dept where rowid='AAASZFAAEAAAACHAAA';
 
DEPTNO DNAME          LOC
------ -------------- -------------
    10 ACCOUNTING     NEW YORK
 
SQL>