Make Postgres dump from Heroku human-readable

When dumping your Heroku Postgre database (with heroku pg:backups:capture --app my-app and heroku pg:backups:download --app my-app), it will result in a binary dump.
If you want your contents to be human-readable (e.g. for moving to a different database system like MariaDB or SQLite), you can transform the file with pg_restore:

pg_restore -f output.sql infile.dump

Note that there is also a flag to omit the schema and output only the data of the dump: --data-only. This may be useful if you can restore the schema otherwise, e.g. when using Rails, through running your migrations. When moving to a different RDBMS, this can come handy because you don't have to convert the column datatypes in the file.