Hi, I'm working on support for embedded associations in CouchDB [1]. Checking how this is mapped by the MongoDB dialect I saw its done like this (here with an order column): { "_id": "123", "orderedChildren": [ { "birthorder": 0, "orderedChildren_id": "456" }, { "birthorder": 1, "orderedChildren_id": "789" } ] } Just looking at this document one can't tell whether "orderedChildren" actually represents an association or an embedded collection. For our engine that's no problem as it knows the kind of the element from its meta-model. We have a testing approach though which makes assertions on the number of associations stored in the database. With the representation described above the number of embedded associations can't be determined on the server-side alone (using a "view" in CouchDB terms). Besides from adding an attribute which describes the kind of a collection (which wouldn't be so nice as it was just for testing purposes), I don't see any other way than obtaining all the candidates and single out actual associations on the client based on the meta-model. Maybe anyone has a better idea? Btw. for MongoDB the problem is ignored by having the assertion method always return true in this case. --Gunnar [1] https://hibernate.atlassian.net/browse/OGM-389