declare
  Cursor c1(cur NUMBER) Is
  select distinct p.profile_id
      from system_c b
           join profile p
                on b.client_id=p.client_id
      where b.system_cid=1234
  Type oper_value Is Table Of c1%ROWTYPE;
  oper_row oper_value;
  cur      NUMBER;
  rows     PLS_INTEGER := 10000;
  i        PLS_INTEGER ;
  n_ProfileId number;

begin
  Open c1(cur); 
    Loop
     Fetch c1 Bulk Collect
     Into oper_row Limit rows;
     Exit When oper_row.COUNT = 0;
     
     Forall i In 1 .. oper_row.COUNT
     select oper_row(i).profile_id
            into n_ProfileId
         from dual;
DBMS_OUTPUT.PUT_LINE(i);
    End loop;
    Close c1;
    oper_row.delete;
end;

for i in ( select distinct p.profile_id
      from system_c b
           join profile p
                on b.client_id=p.client_id
      where b.system_cid=1234)
loop
чото происходит
end loop;