On Nov 8, 2016, at 4:03 PM, stepharo <stepharo(a)free.fr&gt; wrote: Hi doru If I have a model "model1" mse or database it will have internal names/id then I have a delta or even another model and loading it I will need to do a mapping between in memory objects of the model 1 So you propose to remove all the entities related to entities in Model2 from model1 and to load load model2 but to do so you need to know that id:xxx in Model2 corresponds to Class A in Model My impression is that we should really have a uniqueName for any entity. Stef _______________________________________________ Moose-dev mailing list Moose-dev(a)list.inf.unibe.ch https://www.list.inf.unibe.ch/listinfo/moose-dev