I started a project on a Hobby Dev plan (free, limit 10,000 rows), and then later needed to upgrade it to Hobby Basic ($9/month, limit 10,000,000 rows).

After assigning the new database, I had two databases attached to the application. They looked something like this:

• HEROKU_POSTGRESQL_OLIVE (postgresql-dimensional-3321) Old, free-tier (Hobby Dev) database

original: https://gist.github.com/simonw/50e14b9a3e829355d6d43f0f12f91e74

I started a project on a Hobby Dev plan (free, limit 10,000 rows), and then later needed to upgrade it to Hobby Basic ($9/month, limit 10,000,000 rows).

⚠️ In the following, replace <appname> with the name of your Heroku app.