select on NativeQuery trigger full flush immediately as the document says.
the code is :
PersonEntity perosn1 = new PersonEntity(1, "person1");
entityManager.persist(perosn1);
entityManager.remove(perosn1);

AddressEntity addressEntity = new AddressEntity(1, "address1");
entityManager.persist(addressEntity);
entityManager.remove(addressEntity);

System.out.println("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF->1");
assertTrue(((Number)entityManager.createNativeQuery("select count from hibernate_test_person_entity").getSingleResult()).intValue() == 0);
// entityManager.createNativeQuery("delete from hibernate_test_person_entity where id = 1").executeUpdate();
assertNull(entityManager.find(PersonEntity.class, 3721));

the output is:
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF->1
Hibernate:
insert
into
hibernate_test_person_entity
(name, id)
values
(?, ?)
Hibernate:
insert
into
hibernate_test_addres_entity
(address, id)
values
(?, ?)
Hibernate:
delete
from
hibernate_test_person_entity
where
id=?
Hibernate:
delete
from
hibernate_test_addres_entity
where
id=?
Hibernate:
select
count
from
hibernate_test_person_entity
Hibernate:
select
personenti0_.id as id1_1_0_,
personenti0_.name as name2_1_0_
from
hibernate_test_person_entity personenti0_
where
personenti0_.id=?