Does ember-data track values that are dirty or only if the model is dirty, would it be possible for ember to push only the dirty values to the server when you save ? it would be easier then having to get the old version on the server and comparing them, especially for managing relationships using a graph database
POST in REST by definition will send the entire element and not a delta (changes only). That’s how Ember-Data works too.
im talking about PUT, of course post must send the entire element 
It’s a typo, it should have said PUT in REST …
yes, its possible. You would have to extend the serializer for it. The model gets dirty as soon as an attribute is dirty (not the relations, you will have to always send them).
Here is an example: Dirt tracking with Ember-Data - only save dirty properties
But its not perfect. It diesnt work with proper inheritance and screws up embedding. Im working on a better method, but at the moment at least I dont have the time.