JBoss 3.2.6/3.2.7, default setting in standardjbosscmp-jdbc.xml, commit option A used, transaction 'required'
I observed strange selects for two applications. There is relation A -> many B (unidirectional), loid is primary key

a.getBs() gives select:
SELECT LOID FROM B WHERE (A_FK=?)

and now every entity B is accessed by fields, it gives:
SELECT LOID, field1 FROM B WHERE (LOID=?) OR (LOID=?) OR (LOID=?) OR (LOID=?) OR ...

SELECT LOID, field2 FROM B WHERE (LOID=?) OR (LOID=?) OR (LOID=?) OR (LOID=?) OR ...
(it is in 3.2.6, on 3.2.7 I have the same but without loid in select)

and so on for every field. So obviously read-ahead works and eager-load-group doesn't (default * eager group)

Even to be sure I tried to set read-ahead for relation:
<ejb-relation>
<ejb-relation-name>A2Bs</ejb-relation-name>
<ejb-relationship-role>
<ejb-relationship-role-name>A2Bs:A</ejb-relationship-role-name>
<key-fields>
<key-field>
<field-name>loid</field-name>
<column-name>A_FK</column-name>
<jdbc-type>INTEGER</jdbc-type>
<sql-type>INTEGER</sql-type>
</key-field>
</key-fields>

<read-ahead>
on-load
<eager-load-group>*</eager-load-group>
</read-ahead>
</ejb-relationship-role>
<ejb-relationship-role>
<ejb-relationship-role-name>A2Bs:Bs</ejb-relationship-role-name>
<fk-constraint>true</fk-constraint>
<key-fields/>

</ejb-relationship-role>
</ejb-relation>

It didn't change the behaviour.
(by the way loading of main entity A is ok, eager load works properly in this case)

In project we have 100 beans and half of it is in CMR relations - and such selects really kills performance.
The forum topic is: http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3883621.