PosgreSQL 11 Notes

0) Debian instalation
(ref: https://wiki.postgresql.org/wiki/Apt#Quickstart)

sudo apt-get install curl ca-certificates
curl https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
sudo apt-get update
sudo apt-get install postgresql
/* sudo apt-get install pgadmin4 */

1) Getting Started
(ref: https://pgdash.io/blog/postgres-11-getting-started.html)

1.1)
/etc/postgresql/11/main/pg_hba.conf
This file is used to control how PostgreSQL users are authenticated
(https://www.postgresql.org/docs/11/auth-pg-hba-conf.html)

For item 1.3 add this line:
host   userdb   userapp   0.0.0.0/0   md5

1.2)
/etc/postgresql/11/main/postgresql.conf
Remove comment '#' from line and change 'localhost' to '*':
#listen_addresses = 'localhost'
listen_addresses = '*'

sudo systemctl restart postgresql

$ sudo netstat -tnlp | grep 5432
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      8408/postgres

1.3) Creating frist user (userapp) and self database (userdb):
$ sudo -u postgres psql
psql (11.0 (Ubuntu 11.0-1.pgdg18.04+2))
Type "help" for help.

postgres=# create user userapp password 'userpassword';
CREATE ROLE
postgres=# create database userdb owner userapp;
CREATE DATABASE
postgres=#

(or, after 'sudo su postgres', run commands 'createuser --interactive' and 'createdb userdb')

Testing:
$ psql -h 127.0.0.1 -d userdb -U userapp