I am new to postgres and I think I messed up my postgresql, so I want to delete postgresql so that I can reinstall it. The problem is that when I run the following command, the folder /etc/postgresql/9.5 still exists.
sudo apt-get remove postgresql
I also tried:
sudo apt-get --purge remove postgresql
But this did not do the trick either. Does anyone have an idea of how to delete postgresql completely?
You were correct in the command to uninstall postgresql. The /etc/postgresql contains configuration files. You can remove that and other postgres directories yourself using
sudo rm -rf /var/lib/postgresql/
sudo rm -rf /var/log/postgresql/
sudo rm -rf /etc/postgresql/
Base on this answer here, you may also have related packages installed you can list with
dpkg -l | grep postgres
You can remove those using the same command
sudo apt-get --purge remove package-to-be-removed
You can remove all the packages related to PostgreSQL with just one line of code using a wild card *:
sudo apt-get --purge remove postgresql*
This means you remove all the packages which names start from "postgresql", * means "and everything after". While uninstalling you'll be additionally asked to remove the files associated with the postgres, in your case you should agree with that.
Then you can check whether some packages have left, with this command, for example (outputs the list of packages with the names that start with "postgr"):
sudo dpkg -l | grep postgr*
and it should give you no output (i.e. "no packages"). If you're not sure with the latest command, you can check it before removing anything - you will see the list of PostgreSQL packages.
First of all remove postgresql using this command
sudo apt-get --purge remove postgresql
Then list all the postgres related package
dpkg -l | grep postgres
remove all the packages using the following command
apt-get --purge remove packagename1 packagename2 ..
Confirm all the files and folders related to postgres/postgresql are deleted and delete using rm command
whereis postgres
whereis postgresql
delete the postgres user using the command
userdel -f postgres
