[hibernate-issues] [Hibernate-JIRA] Created: (HHH-5143) Lazy Loading Not Working for @OneToOne Associations With LazyToOneOption.PROXY

[j nadler (JIRA)]

Lazy Loading Not Working for @OneToOne Associations With LazyToOneOption.PROXY
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                 Key: HHH-5143
                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-5143
             Project: Hibernate Core
          Issue Type: Bug
          Components: core
    Affects Versions: 3.5.1
         Environment: Hibernate Core 3.5.1-Final, MySQL 5.1
            Reporter: j nadler


I'm using 3.5.1. Two persistent entities, parent and child, are in a one to one relationship:

In Parent, the reference to Child:
   @OneToOne(optional=false, fetch=FetchType.LAZY, cascade={ CascadeType.MERGE, CascadeType.REMOVE, CascadeType.REFRESH, CascadeType.PERSIST })
   @LazyToOne(LazyToOneOption.PROXY)
   @JoinColumn(name = "childId")
   @ForeignKey(name="FK_Parent_Child")
   @IndexedEmbedded()
   public Child getChild() {
      return child;
   }
   public void setChild(Child child) {
      this.child = child;
   }


And in Child, the reference to Parent:

   @OneToOne(mappedBy="child", fetch=FetchType.LAZY)
   @LazyToOne(LazyToOneOption.PROXY)
   @ContainedIn 
   public Parent getParent() {
      return parent;
   }
   public void setParent(Parent parent) {
      this.parent = parent;
   }


When I load a Parent entity via HQL, I see three SQL queries:
-one that corresponds to my HQL query
-one that loads Child
-one that loads Parent from the Child's perspective

I'm watching it in JProfiler and it's hurting our app performance significantly because Child contains LOBs that are rarely needed.

I tried making it a unidirectional association (no reference from Child back to Parent) but the expensive SQL call (loading Child) still happens.  That gets it down to two SQL queries:
-one that corresponds to my HQL query
-one that loads Child (the expensive one)

We are using the stock javassist proxies and no bytecode enhancement.



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