create table tree0 (
  id integer not null primary key,
  p integer,
  v integer 
);

insert into tree0 values
  (11, null, null),
  (12, 11, null),
  (13, 11, null),
  (14, 11, 4000),
  (15, 12, 1000),
  (16, 12, 1100),
  (17, 13, null),
  (18, 13, 300),
  (19, 17, 500),
  (20, 17, 501),
  (21, 17, 502)
;