How to get a list of parent IDs?

Question

PostgreSQL

There is a comments table

comment (
  id_comment          integer PRIMARY KEY ,
  path                integer[] not null,
  content              text,
  rating              integer
)

Need to get high rated comment first works fine, but if a child comment has a higher rank than the parent or other comment it will output it first. And I would like to sort by rating only the first parent and those who do not have "children" in short, we have:
SELECT * FROM comment ORDER BY rating DESC LIMIT

id |  path   |    content                     | rating
----+---------+--------------------------------+---------
  1 | {1}     | я комментарий 1                | 1
  2 | {1,2}   | я дочь        комментария 1    | 5
  3 | {3}     | я комментарий 3                | 3
  4 | {4}     | я  комментарий 4               | 2
  
результат сортировки  должен быть :
 id |  path   |    content                     | rating
----+---------+--------------------------------+---------
  3 | {3}     | я комментарий 3                | 3
  4 | {4}     | я комментарий 4                | 2
  1 | {1}     | я комментарий 1                | 1
  2 | {1,2}   | я дочь комментария 1           | 5

I'm using the Materialized Path pattern.

Answer 1

https://www.postgresql.org/docs/current/static/fun...
array_length

SELECT * FROM comment ORDER BY array_length(path, 1) ASC, rating DESC

Answer 2

Isn't it better to recursively take the whole chain, and collect the rating of children like avg for example?