Handling multiplicity in object databases
Collections and arrays introduce new levels of complexity to
the structured objects first discussed in
The busy Java™
developer's guide to db4o: Beyond simple objects.
Fortunately, db4o isn't the least
bit fazed by handling multiplicity relationships -- and neither should you be.
18 Sep 2007, by Ted Neward (ted@tedneward.com), Principal, Neward & Associates
http://www.ibm.com/developerworks/java/library/j-db4o5.html?ca=drs-