Heroku - Rails 3 to 3.1 migration issues with PostgreSQL: relation "users" does not exist
I was able to solve this by myself.
One of my initializer files was doing a find_or_create_by_id which worked fine while development, but since I was now deploying on a fresh new application, the absence of tables was the source of that error, and was also blocking the migrate command from running and creating the missing tables.
It had nothing to do with syntax of PostgreSQL.
Look at the first error message: "ERROR: must be owner of database hvifyyqdjs"
You (or your program) are not allowed to drop it.