[idunno246]

We've been using alembic in Python. It makes a dag, and has a concept of merge points so you Don't grow leaves indefinitely. Handles branching well, our history mostly just looks like a line of diamonds.

You're sol if the branches touch the same column or directly conflict, but that's never happened to us. Rarely dev Dbs end up hosed, if someone commits a bad change for instance and you pull it in before fixed, but since the latest alembic bug fixes and solid pr ci t hasn't happened.