Then new dev plans support hstore: https://postgres.heroku.com/blog/past/2012/4/26/heroku_postg...
I'm kind of in a no-mans land of Heroku data plans - until today!
But what is the use case for a dev databases with 'much more than 5MB of data' ?
My dev machine has a much smaller set of data, but on Heroku, I run stage servers with reasonable amounts of real life data that I need for final testing