2👍
You can use Heroku CLI to check which are the available add-ons by heroku:
heroku addons
There are some other databases which you can use for deploy on heroku like:
Heroku Postgres:
There are paid service of heroku postgres available with plans, pricing of heroku postgres.
There are some 3rd party add-ons which you can use in postgres too =>
ElephantSQL
, mLab
, clearDB
👤Myth
Source:stackexchange.com