Dear All,

I am using Hibernate 2.1 version. I set cascade=save-update option in Hibernate configuration so that each parent object upon Save gets saved as well as its children. I was wondering if Hibernate has any kind of mechanism where it will update only those tables of which corresponding POJOs or objeects got modified ? I am just concerned about extra overhead involved in all possible children tables updates.

Thank you.
Ram Mahajan

As long as you stay within session scope, only dirty objects will get updated.

Outside of session scope, you can use select-before-update

Well, in my case, the objects go out of session scope.

1. The presentation layer requests a deep copy of parent object, then it modifies the parent object as well as some of its children objects as per the form data. The session at this point is closed.
2. After modifying the parent/child objects, the presentation layer calls businees and then Data layer to save it.
3. The data layer will again gets the session associated with the same thread. As the session is already closed, it will open a new session and does the saveOrUpdate operation.

In above scenario, I am worndering if Hibernate will update entire tree of parent object or will it only update the corresponding tables of modified objects ?

I do not see dirty bits in the POJO itself, so wondering how Hibernate will ever know the object's set method is called out of the session. If it does not, will it update unnecessary tables which might be an overhead.

Thank you.
Ram Mahajan