Only first level. We could get the name of the field you are looking for, but not the all tree. For example you are looking for struct_field.id_toto, you will only know that you want the column which contains struct_field but not the id only. So we will ask parquet to read the all struct. Very bad.

We found in one of the hive object, that we can access to the name 'id_toto' for example but you don't know where it belongs to. If you have many struct with this beautiful name, you will not be able to know which one is from. ( no tree , just the last name)