I'm running MX Linux 21 and recently installed PostgreSQL-13; I wanted postgres to have read, write and execute access to a certain folder therefore I added the unix user postgres to the group of owner and granted such accesses to the group. The commands was: setfacl -R -m u:postgres:rwx myfolder
Then I uninstalled postgresql from MX package manager completely (i.e., sudo apt remove postgresql-13).
I thought the unix user called postgres should be gone with the removal of postgresql, it however was not the case. I am still able to do sudo su postgres and logged in as the user postgres.
I then did sudo deluser postgres and it failed with exit code 8, saying there's process still running on postgres.
I then did a ps -ef and found that sudo su postgres is the main process that held up the deletion of user postgres. I killed that process in htop and ran sudo deluser postgres again with success.
But when I checked with getfacl to see if the unix user postgres has been deleted from the user group, I found this:
$ getfacl myfolder
# file: owner
# owner: owner
# group: owner
user::rwx
user:121:rw-
group::rwx
mask::rwx
other::r-x
that user:121 is in place of user postgres.
Does this mean installing postgres is leaving a trace in my system and I can't purge it?
Does this mean installing postgres would always make an user postgres in my system and if I don't delete it, it'll be there forever?
