Exactly to the point, that’s what I mean when I said I don’t rely on the application logic to accomplish something that might eventually be available in dgraph as they exists in the other DBs.
One other use-case of having native support such queries would be to remove duplication of application logic from multiple services/client-side-apps.
Let’s say I implement the groupby at application level and later I require the same groupby in another service, I will have to duplicate the same stuff whereas If we can support it in the custom DQL. I can add that query in @custom directive and use it in multiple places.