Since the adapter is unaware of the user setup, global is a good choice, as it works regardless of whether the node is in a cluster. The adapter is still very much in the exploration stage but is usable. With the occasional bugs here and there that I’m finding while building a different product.
I think it might be worth proposing in https://groups.google.com/g/elixir-ecto to make Ecto.Migrator a behaviour and move that and Ecto.Migration into ecto main and have adapters implementing them since we both could use the flexibility and control that would bring. And it might get some more clarity over the choice already made, which is unclear for both of us, and I’m sure there will be other people in the future running into this.
/edit
Keep in mind that some people don’t use global since AFAIK the regular Erlang distribution is a full mesh, and that can bring some pain when running a large cluster, However, I don’t believe that running one large cluster is a silver bullet, and there might be more gains by divide and conquer and running multiply full mesh clusters that can communicate.
