rails/rails — pull request #14441 by cap10morgan (2014-03-21 00:40:04+00:00)
Title: add row_format option for mysql tables

This allows MySQL 5.6.x users to better support utf8mb4 (a.k.a. real
UTF-8) by using DYNAMIC row format tables that allow longer indexes.

You would put this in your database.yml in that case:
`row_format: dynamic`

I'm happy to add a test or two for this if anyone can suggest the right place to put it.