I have a very simple pice of code:

Query query = session.createQuery("from Site as site");
query.setFetchSize( 10);
List list = query.list();
v.addAll(list);

My problem is that these lines lead in a n+1 queries to the database.

The mapping for the Site object is:
<hibernate-mapping>
<class name="com.lauerbach.jcms.beans.Site"
lazy="false"
batch-size="10">
...


How do I define eager loading directly for the entity that is selected?
Is there a similar mechanism as in the CMP-Engine on JBoss? There I can define load-groups on the finders to load a set of properties eagerly.

So how do I define a load-group for a single query?
Or at least, how do I load all fields directly with the finder?

Show your mappings as we cannot see the relationships.
In anycase, read about 'left join fetch' and use it on the fields you wish to eager load with the query, eg, Many-to-one rels etc.

No my Object does not have any relations. Assume this object just stores properties.
In the documentation and in several how-tos i found dozens of load optimization on relations, but not on the load of the object itself.
I already tried to define lazy="false" of the object itself. But I still get the n+1 queries to the database.

What is the type of v, and what does the addAll() method do? The query should be initializing everything for you, so this is the only point where I could see extra fetches happening. (Note, this isn't n+1, but just n -- besides, n + 1 usually refers to when you have a one-to-many relationship. You get one select for the "one" side of the relationship and "n" selects as you access and lazy load each member of the associated "many" side of the relationship.)

Variable v is a simple java.util.Vector and does not matter at this point (sorry for inserting here).


Here is the relevant part of may console-log, you can clearly see the n+1 queries:

12:24:04,231 INFO [STDOUT] Hibernate: select this_.siteID as siteID0_,this_.name as name10_0_ from Site this_

12:24:04,387 INFO [STDOUT] Hibernate: select rubrics0_.site as site__, rubrics0_.rubricID as rubricID__, rubrics0_.rubricID as rubricID0_, rubrics0_.description as descript2_9_0_, rubrics0_.title as title9_0_, rubrics0_.site as site9_0_, r
ubrics0_.parentRubric as parentRu5_9_0_ from Rubric rubrics0_ where rubrics0_.site=?

12:24:04,403 INFO [STDOUT] Hibernate: select rubrics0_.site as site__, rubrics0_.rubricID as rubricID__, rubrics0_.rubricID as rubricID0_, rubrics0_.description as descript2_9_0_, rubrics0_.title as title9_0_, rubrics0_.site as site9_0_, rubrics0_.parentRubric as parentRu5_9_0_ from Rubric rubrics0_ where rubrics0_.site=?

12:24:04,403 INFO [STDOUT] Hibernate: select rubrics0_.site as site__, rubrics0_.rubricID as rubricID__, rubrics0_.rubricID as rubricID0_, rubrics0_.description as descript2_9_0_, rubrics0_.title as title9_0_, rubrics0_.site as site9_0_, rubrics0_.parentRubric as parentRu5_9_0_ from Rubric rubrics0_ where rubrics0_.site=?

12:24:04,403 INFO [STDOUT] Hibernate: select rubrics0_.site as site__, rubrics0_.rubricID as rubricID__, rubrics0_.rubricID as rubricID0_, rubrics0_.description as descript2_9_0_, rubrics0_.title as title9_0_, rubrics0_.site as site9_0_, rubrics0_.parentRubric as parentRu5_9_0_ from Rubric rubrics0_ where rubrics0_.site=?

sh..., it IS the relation that is loaded +x.

Yeah, looks like its the relationship with Rubric (I'm assuming that's the classname). Can you post your mappings for Site and Rubric? I'm a bit confused as to why you're loading Rubric, since the query didn't ask for it.