> how to dynamically, using fetch plan, exclude (rather than adding) to the fetch plan some attribute not to retrieve
I probably misunderstand, but doesn't FetchPlan.clearFields() + FetchPlan.clearFetchGroups() followed by a few addField() do what you want (I haven't tried) ? http://openjpa.apache.org/builds/1.2.1/apache-openjpa-1.2.1/docs/javadoc /org/apache/openjpa/persistence/FetchPlan.html
