Large Collection « Collection « JPA Q&A





1. large collections in hibernate.    coderanch.com

Hi guys. I am trying to do a query on a table with four million records. I've set everything to "lazy" and additionally have even tried setting cachemode to IGNORE. Neither effort seems to be saving me. I'm still getting the following dreaded error : Exception in thread "main" java.lang.OutOfMemoryError: Java heap space. This seems like it should be simple. Is ...

2. Collections returned padded with large amounts of 'nulls'    forum.hibernate.org

Newbie Joined: Tue Jan 06, 2004 5:57 am Posts: 3 A mapping that involves objects with member collections (mapped as a many-to-one List) works well apart from the fact that the resultant List contains a lot of padding with null references. Is this normal? Do I have to trim these Lists at the time the objects are hydrated or is it ...

3. Large graph with serveral collections woes...    forum.hibernate.org

Author Message rollatwork Post subject: Large graph with serveral collections woes... Posted: Thu Sep 16, 2004 4:53 pm Regular Joined: Tue Dec 09, 2003 2:39 pm Posts: 106 Location: Toronto, Canada Problem Description Our use case requires that we build a tree of our entity, Subject, and pass it all the way to our rich client. Subject has four ...

4. Large Hibernate Collection best practices    forum.hibernate.org

I have a large Hibernate collection question: Consider the following objects: User UserCommunityRole Community Where a User can enroll in many Communities, and a Community can have many Users. The UserCommunityRole object maintains state about the role. In this case a Community can have a large number of users, say 50,000. What are the best practices for describing this to Hibernate. ...

5. Another large collection question - maybe simple    forum.hibernate.org

That is a great point, and one I forgot to address in my original question. I was looking at using setFirstResult and setMaxResults, but I am terrified that the order from the database is not guaranteed, and that iterating though the list this way might leave some objects un-retrieved and other doubly-retrieved. Is this a possibility?

6. LARGE COLLECTION    forum.hibernate.org

7. Pulling one instance from a large lazy collection    forum.hibernate.org

I have an object that has a collection which can contain many objects (let's say 30,000 or so). I need the ability to pull one instance by id from the collection for display on the UI. I'd originally thought that using filtered collections might be the way to get that done but Hibernate filters are a bit more course-grained than that. ...