Lazy loading not working with Specification

I have migrated to spring v2.1.2.RELEASE and using hibernate version 5.3.7.FINAL

We have @OneToOne bi directional relationship between entity as follows

class Parent{

    @OneToOne(fetch = FetchType.LAZY, mappedBy = "parent", optional = false)
    @NotAudited
    private Child child; 

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
}

class Child{
    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "parent_id")
    @MapsId
    @NotNull
    private Parent parent;

    @Id
    @Column(name = "indent_id", insertable = false, updatable = false)
    private Integer parentId;

}

calling

parentRepository.findByIdIn(Collections.singletonList(1));

makes db call as:
Hibernate:

select parent0_.id as id1_19_ from  parent parent0_ where parent0_.id in (?)

Which is working fine, now consider use case,

public class Filter implements Specification<Parent> {

		@Override
		public Predicate toPredicate(Root<Indent> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
			// TODO Auto-generated method stub
			List<Integer> parentIdList = new ArrayList<>();
			parentIdList.add(1);
			ArrayList<Predicate> predicates = new ArrayList<>();
			predicates.add(root.get("id").in(parentIdList));
			return predicates.size() == 0 ? null
					: criteriaBuilder.and(predicates.toArray(new Predicate[predicates.size()]));

		}

	} 



    PageRequest pageRequest = PageRequest.of(page - 1, pageSize, Sort.Direction.DESC, "id");
	Filter filter = new Filter();
	Page<Indent> indentPage = indentRepository.findAll(filter, pageRequest);

makes DB call to Child entity as well

Hibernate:
select parent0_.id as id1_19_ from  parent parent0_ where parent0_.id in (?)
select child0_.parent_id as parent_i1_29_ from child child0_ where child0_.indent_id in (?)

Is there any way to avoid Db call to child entity here?

You can define an entity graph to specify a pattern that can be passed to a query to determine which attributes you want to be fetched. Attributes that are not included in the graph will be treated as LAZY by persistence provider.

    @Entity
    @NamedEntityGraph(name = "only_id", attributeNodes={@NamedAttributeNode("id")})
    class Parent{
    
        @OneToOne(fetch = FetchType.LAZY, mappedBy = "parent", optional = false)
        @NotAudited
        private Child child; 
    
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        private Integer id;
    }

JPA API:

EntityGraph entityGraph = entityManager.getEntityGraph("only_idh");
// define your query
query.setHint("javax.persistence.fetchgraph",graph);

More details : https://docs.oracle.com/javaee/7/tutorial/persistence-entitygraphs002.htm

With Spring Data JPA

 public interface MyRepository extends JpaRepository<Parent, Integer> {
 
    @EntityGraph(value = "only id")
    Parent findById(Integer id)

More details : https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#jpa.entity-graph

JpaSpecificationExecutor :

public interface MyRepository extends JpaSpecificationExecutor<Parent> {
   @Override
   @EntityGraph(attributePaths = {"only_id"}, type=EntityGraphType.FETCH)
   Parent findByOne(Specification<Parent> spec);
}

More details : https://docs.spring.io/spring-data/jpa/docs/current/api/org/springframework/data/jpa/repository/JpaSpecificationExecutor.html

JPA provider usually takes fetch type Lazy as a hint, so may be in your case its not considering it at all. check below

> fetch public abstract FetchType fetch (Optional) Defines whether the
> value of the field or property should be lazily loaded or must be
> eagerly fetched. The EAGER strategy is a requirement on the
> persistence provider runtime that the value must be eagerly fetched.
> The LAZY strategy is a hint to the persistence provider runtime. If
> not specified, defaults to EAGER. Default: EAGER

JPA Doc