PB txns in OJB Query / ODMG mix?

[Steven Richman <ju...@shift9.com>]

Hi,

I'm a new OJB user. I just implemented support for using OJB Queries with
ODMG, as discussed in the FAQ "I don't like OQL, can I use the
PersistenceBroker Queries within ODMG?"

The FAQ says to consult org.apache.ojb.odmg.oql.OQLQueryImpl.execute() to
see how to do it. It also offers a code example that contains

        Transaction tx = OJBFactory.getInstance().currentTransaction();
        PersistenceBroker broker = ((HasBroker) tx).getBroker();
        broker.beginTransaction();
        ManageableCollection result =
            (ManageableCollection) broker.getCollectionByQuery(
                this.getCollectionClass(),
                query);
        broker.commitTransaction();
        ...

However, the code in OQLQueryImpl.execute() never calls
PersistenceBroker.beginTransaction()/commitTransaction(). Are these calls
necessary, or can I safely omit them? I don't really understand what's
going on with the two kinds of transactions (PB and ODMG) in the above
code, so if someone can clarify I'd appreciate it.

Thanks,
steven.