Version 6
Created by gbadner on Jan 19, 2018 6:20 PM. Last modified by gbadner on Feb 25, 2020 5:31 PM.

    This page is an old working document and is probably out of date.

     

    Introduction

     

    This document describes how Hibernate currently behaves in Hibernate ORM master branch with various mappings for lazy @OneToOne/@ManyToOne.

     

    It also describes possible improvements.

     

    Unidirectional one-to-one:

     

    @Entity

    public class Owner {

         @OneToOne( fetch = FetchType.LAZY )

         private Lazy lazy;

    }

     

    Join Column@LazyToOne Mappinghibernate.enhancer.enableLazyInitialization = falsehibernate.enhancer.enableLazyInitialization = true

    FK references PK of associated entity

    		not specifiedIs Owner#lazy initialized by Session#get( Owner.class, id )? false
    Is Owner#lazy a HibernateProxy? true
    LazyToOneOption.FALSE

    Is Owner#lazy initialized by Session#get( Owner.class, id )? true (separate statement)

    Is Owner#lazy a HibernateProxy? false

     

    Improvement: log a warning: <association-path> is mapped as FetchType.LAZY and @LazyToOne(LazyToOneOption.FALSE), which are incompatible. When the owner is loaded, the association will loaded eagerly by a separate query.

    Is Owner#lazy initialized by Session#get( Owner.class, id )? true (separate statement)

    Is Owner#lazy a HibernateProxy? false

     

    Improvement: log a warning: <association-path> is mapped as FetchType.LAZY and @LazyToOne(LazyToOneOption.FALSE), which are incompatible. When the owner is loaded, the association will loaded eagerly by a separate query.

    LazyToOneOption.NO_PROXY

    Is Owner#lazy initialized by Session#get( Owner.class, id )? true

    Is Owner#lazy a HibernateProxy? false


    Improvement: log a warning: <association-path> is mapped as FetchType.LAZY and @LazyToOne(LazyToOneOption.NO_PROXY), but hibernate.enhancer.enableLazyInitialization = false, which is incompatible. hibernate.enhancer.enableLazyInitialization must be true to work with LazyToOneOption.NO_PROXY. When the owner is loaded, the association will loaded eagerly by a separate query.

    Is Owner#lazy initialized by Session#get( Owner.class, id )? false

    Is Owner#lazy a HibernateProxy? false

    LazyToOneOption.PROXYEquivalent @LazyToOne not specified.

    Is Owner#lazy initialized by Session#get( Owner.class, id )? yes

    Is Owner#lazy a HibernateProxy? false


    Improvement: log a warning: <association-path> is mapped as FetchType.LAZY and @LazyToOne(LazyToOneOption.PROXY), but hibernate.enhancer.enableLazyInitialization = true, which is incompatible. hibernate.enhancer.enableLazyInitialization must be false to work with LazyToOneOption.PROXY. When the owner is loaded, the association will loaded eagerly by a separate query.

    FK references non-PK of associated entity

    		not specified
    LazyToOneOption.FALSE
    LazyToOneOption.NO_PROXY
    LazyToOneOption.PROXY
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