create table test_tbl (ts_col timestamp(0), n_col number)

create or replace function f ( p int )  
  return int as 
begin 
  return p; 
end f; 

declare 
  l_cnt pls_integer := 0; 
begin  
  for c_rec in ( 
            select /*+ findme_plsql */ 
                   * 
            from   test_tbl 
            where  ts_col >= to_timestamp('01-MAR-19', 'dd-MON-yy') 
            and    ts_col <  to_timestamp('31-MAR-19', 'dd-MON-yy') + 1 
            and    ts_col < date'2019-03-31' 
            and    n_col = 1 
            and    f ( 1 ) = 1  
             ) 
  loop 
    l_cnt := l_cnt +1; 
  end loop; 
 
  dbms_output.put_line('how many='||l_cnt); 
end; 

select sql_fulltext,sql_id 
from v$sql 
where upper(sql_fulltext) like 'SELECT /*+ FINDME%'