Using V$SQL_PLAN_MONITOR to count the STARTS in a SORT JOIN operation

create table tq84_A (id number(5) not null, dat varchar2(6) not null, val number(4,1) not null);
create table tq84_B (id number(5) not null, dat varchar2(6) not null, val number(4,1) not null);

insert into tq84_A
select
   level,
   case when level not in (250, 500, 750) then
      (100-mod(level, 100)) || 'hay'
   else
      'needle'
   end,
   level / 10
from
   dual connect by level <= 1000;
   
insert into tq84_B
select
   level,
   case when level not in (200, 400, 600, 800) then
      (100-mod(level, 100)) || 'hay'
   else
      'needle'
   end,
   level / 10
from
   dual connect by level <= 1000;


begin
   dbms_stats.gather_table_stats(user, 'tq84_A');
   dbms_stats.gather_table_stats(user, 'tq84_B');
end;
/

select /*+ monitor */ /* find-me */
   a.id  id_a,
   b.id  id_b,
   a.val val_a,
   b.val val_b
from
   tq84_A a                 join
   tq84_B b on a.id < b.id
where
   a.dat = 'needle' and
   b.dat = 'needle';

select
   plm.starts,
   substr(rpad(' ', plm.plan_depth * 2 ) || plm.plan_operation || ' ' || plm.plan_options, 1, 30) op,
   substr(plm.plan_object_name, 1, 6)                                                             obj,
   plm.output_rows
from
   v$sql_plan_monitor plm
where
   plm.sql_id = (select sql_id from v$sqlarea where sql_text like 'select /*+ monitor */ /* find-me */%')
order by
   plm.plan_line_id -- Probably not needed
;
--
--     STARTS OP                             OBJ    OUTPUT_ROWS
-- ---------- ------------------------------ ------ -----------
--          1 SELECT STATEMENT                                6
--          1   MERGE JOIN                                    6
--          1     SORT JOIN                                   3
--          1       TABLE ACCESS FULL        TQ84_A           3
--          3     SORT JOIN                                   6
--          1       TABLE ACCESS FULL        TQ84_B           4

drop table TQ84_A;
drop table TQ84_B;