Note: I can see this is really the case by turning the log level to TRACE. When using a Map inside an entity (either with a String value or an Entity value) I always get N+1 select problems when I select multiple entities. This gives inacceptable performance (e.g. we have several hundred products that can in theory be easily fetched under a second but takes > 10 seconds).
https://issues.apache.org/jira/browse/OPENJPA-1920 Because of this problem I turned my Map into a OneToMany List of entities that contains the map key and somehow I still have the N+1 select problem which is odd because I normally don't have it on OneToMany. I already solved a similar N+1 select problem before on tree structures by starting out without having a node's parent in the fetchplan but with the children, then fetch all nodes, then add the nodes parent in the fetchplan and select the root nodes. Regards, Henno Vermeulen Huize Molenaar
