I have an Item class that has a collection bids.
By default (Hibernate 3) my pojo is lazy so when I want to getBids() I need first to Hibernate.initialize(item) so as later to have item.getBids();

Correct?

I read in a book that I use another lazy strategy and do something like that:
Criteria criteria = session.createCriteria(Item.class);
criteria.setFetchMode("bids", FetchMode.JOIN);
List allItems = criteria.list();

I can have bids by using a single SQL query.
How exactly does it mean?The above gives me allItems. If I iterate the collection to get bids won't I have again new sql executions??

Which of the 2 ways is the best?

If you load the object then Access (which in session) or Hibernate.initialise there will be two queries to the DB.

If you use HQL or Criteria the join fetch the collection then only a single (larger) query the the DB will be required to collect the data.

One query maybe more efficient than two (DB speed, network latency etc).

ok I understood but the thing is with join fetch I get all the items correct?
If I go to get the bids won't I have new sql queries?

If you 'join fetch' then this will collect all items in the collection so walking the collection will not cause the collection query to be re-issued.

ok thank you for your answers...Can I also ask another question? I have my pojo item which is lazy and the collection bids which is also lazy. Shouldn't I have a Hibernate Initialization exception when I do item.getBids()? ..The thing is that I don't have any exception.I thought that in order not to have any exception I should do Hibernate.initialize(item.getBids). Don't we use this anymore in Hibernate 3?