Three commands have been promoted from the pg-extras CLI plugin to the CLI proper.
heroku pg:ps lists currently running queries, while
pg:killall can cancel those queries. Full documentation is in the Heroku Postgres article.
Rather than specifying the full URL of a database to
--follow from another app, you can now pass an argument of the form
appname::HEROKU_POSTGRESQL_COLOR_URL. More information on fork and follow can be found in their respective articles.