I've built dozens of Erlang apps and used ETS in every one. I've used Mnesia once, and it was not a pleasant experience. Most Erlang dev teams use ETS directly.

I've built dozens of Erlang apps and used ETS in every one. I've used Mnesia once, and it was not a pleasant experience. Most Erlang dev teams use ETS directly. It's possible to use Mnesia successfully but I see it far less often than ETS these days.