create table t_build as 
       select rownum id
            , trunc(dbms_random.value(1,4)) c1 
         from dual 
      connect by level<=10000;

 create table t_probe as 
 select trunc(dbms_random.value(1,8)) c1 
   from dual 
connect by level<=1000000;

execute dbms_stats.gather_table_stats('SCOTT','T_BUILD')

execute dbms_stats.gather_table_stats('SCOTT','T_PROBE')

select /*+ use_nl(b p) */ * 
  from  t_build b
      , t_probe p
 where  b.c1=p.c1

/

select * from table(dbms_xplan.display_cursor('913xat8gctujw',null,'allstats last +cost'));

PLAN_TABLE_OUTPUT
---------------------------------------------------------------------------------------------------------------------------------
SQL_ID  913xat8gctujw, child number 0
-------------------------------------
select /*+ use_nl(b p) */ *                    from  t_build b
                        ,t_probe p                    where b.c1=p.c1

Plan hash value: 4283443859

-----------------------------------------------------------------------------------------------------
| Id  | Operation          | Name    | Starts | E-Rows | Cost (%CPU)| A-Rows |   A-Time   | Buffers |
-----------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |         |      1 |        |  4296K(100)|  36991 |00:00:00.03 |    2873 |
|   1 |  NESTED LOOPS      |         |      1 |   1388M|  4296K  (2)|  36991 |00:00:00.03 |    2873 |
|   2 |   TABLE ACCESS FULL| T_BUILD |      1 |  10000 |     7   (0)|      1 |00:00:00.01 |       4 |
|*  3 |   TABLE ACCESS FULL| T_PROBE |      1 |    138K|   430   (2)|  36991 |00:00:00.02 |    2869 |
-----------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   3 - filter("B"."C1"="P"."C1")


21 rows selected.