An ETS (Erlang Term Storage) backed Ash Datalayer.

This was initially built for testing purposes, since it comes built into OTP. This makes it possible to test resources easily, quickly and in isolation from the data layer. While this data layer can be used in your application, it should only be used for small/unimportant data sets that do not require long term persistence.

The Ets datalayer can not perform transactions. This means that in place updates to many_to_many relationships, as well as relationships where the foreign key is stored on the destination table, are not possible. Separate requests will have to be made to those resources.