Setup Ubuntu 20.04 Focal Fossa Discussion
Here's yet another easier installation method:
https://www.ruby-lang.org/en/news/2018/11/08/snap/
should be:
sudo apt install postgresql-12 libpq-dev
instead of:
sudo apt install postgresql-11 libpq-dev
cheers.
If you want to install postgresql-11 follow steps in this tutorial:
https://computingforgeeks.com/install-postgresql-11-on-ubuntu-linux/