Java Hibernate 4.2中@OneToMany的性能-单向与双向

我只需要一个单向的关系，但在性能方面，我想问什么是最佳实践

我用Junit做了一个测试，双向的结果是：1.9s和单向代码2.4s，看起来单向需要更多的时间

我正在使用Hibernate4.2.21

@单向2.4s

父类

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinColumn(name = "parentuni_id")  
private Set<ChildUni> childs;

Hibernate: select nextval ('parentuni_seq')
Hibernate: select nextval ('childuni_seq')
Hibernate: select nextval ('childuni_seq')
Hibernate: insert into parentuni (parentuni_name, parentuni_id) values (?, ?)
Hibernate: insert into childuni (childuni_name, childuni_id) values (?, ?)
Hibernate: insert into childuni (childuni_name, childuni_id) values (?, ?)
Hibernate: update childuni set parentuni_id=? where childuni_id=?
Hibernate: update childuni set parentuni_id=? where childuni_id=?

@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "parent")
private Set<Child> childs;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "parent_id", nullable = false)
private Parent parent;

Hibernate: select nextval ('parent_seq')
Hibernate: select nextval ('child_seq')
Hibernate: select nextval ('child_seq')
Hibernate: insert into parent (parent_name, parent_id) values (?, ?)
Hibernate: insert into Child (child_name, parent_id, child_id) values (?, ?, ?)
Hibernate: insert into Child (child_name, parent_id, child_id) values (?, ?, ?)

它说，在中国

偏好双向关联：

• 单向关联更难查询。在大型应用程序中，几乎所有关联都必须能够在查询的两个方向上进行导航

有用的资料来源：

希望这有帮助