Hibernate optimization for delete severals objects

Question

In a Java EE application with hibernate, in a big table, I want to purge some millions of objects.

For example

I get some objects that i want to purge: 2000 objects returned over 5000 objets in the tab
and then I want to remove them

Actually while object exists i do:

        List<Object> objectList = this.getObjectManager()
                .getObjectsByCriteria(clientName, objectType, MAX_OBJECTS);
        for (final Object object : objectList) {
            if (logger.isDebugEnabled()) {
                logger.debug("will delete " + object);
            }
            this.getMManager().removeEntry(object);
            counter++;
        }


public void removeObject(final Object object) {
    final Session session = this.getHibernateUtil().getSession();
    session.delete(entry);
    session.flush();
}

I guess that hibernate removes all objects at the commit of the transaction, and not one by one.

What is the best solution in order to remove 2000 objects for example and not have memory or hibernate exceptions?
How to remove really one by one with hibernate?

danny.lesnik · Accepted Answer · 2011-10-04 10:30:28Z

3

Don't fetch them, just use some criteria for deletion. Use HQL for such cases

session.createQuery("delete from MyClass where ...").setXXX(...).executeUpdate();

answered Oct 4, 2011 at 10:30

danny.lesnik

18.6k31 gold badges142 silver badges206 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

superscral Over a year ago

So if the HQL query return 2000 objects, it will not have hibernate or memory issue?

danny.lesnik Over a year ago

When you delete it using HQL they are not loaded they just got deleted.

superscral Over a year ago

And if my HQL delete must delete 276 000 objects, it will works? :D

MikkolidisMedius Over a year ago

It will work with any amount of objects. Hibernate will simply convert the command to SQL and pass it to the database, no objects will be loaded.

Collectives™ on Stack Overflow

Hibernate optimization for delete severals objects

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related