text: --------------------------------------------------------------------------------
  --Example #14: Re-do previous example (Retrieves names of the heaviest/lightest male/female child)
  --------------------------------------------------------------------------------
  select c.*
        , first_value(c.firstname) over (partition by c.gender 
                                         order by c.weight
                                         rows between unbounded preceding
                                                  and current row) as lt_child
        , last_value(c.firstname) over (partition by c.gender 
                                        order by c.weight
                                        rows between unbounded preceding
                                                 and current row) as hv_child
    from childstat c
  ;
  