Erlang: Mnesia or Mysql? [closed]

What DBMS do you use with Erlang ? and Why ?

Is Mnesia in memory?

Mnesia is often underplayed as an in-memory cache and is seldom used alone in production. The first part of the talk is to present a few case studies of using only Mnesia as the production database engine for large throughput services.

Mnesia, because it's all native erlang, and being able to store erlang terms is just great. Speeds up development too.

I know of no other DMBS that can integrate so closely with the language (that one's easy, Mnesia is almost part of the language, a Dict on steroids). Of course, it's a bit low-level, so functions like full-text search have to be coded against it, but it wouldn't be that much fun otherwise (unless you can couple it with some other open-source full-text search engines).

But you have to judge the different options for yourself against your own requirements.