Last year I also reported an N+1 select problem with simple Maps that gives the same "load field" trace and may well have the same cause. https://issues.apache.org/jira/browse/OPENJPA-1920
About the issue reported here by Sirisha and also experienced by me... The problem means that almost all objects deep in the graph structure can get fetched with a single query per object. These can be very many and should normally be efficiently fetched with a single or perhaps a few fixed queries. This problem can already occur when simply having an entity with a OneToOne or ManyToOne relation that has relations of its own. This seems to me to be extremely common. This is such a huge performance issue that I am really flabbergasted that no one else has reported it yet.