Install PostgreSQL on Ubuntu 18.04 | Hostvento Knowledge Base

Tip: Ubuntu 18.04 is old. Newer Ubuntu versions use almost the same steps.

What is PostgreSQL?

A database is a place where programs store information, like a big filing cabinet. PostgreSQL, often called Postgres, is a free and popular database. Websites and apps use it to keep users, orders and posts.

Steps

Log in to your server with SSH. SSH lets you type commands on a remote computer.
Update the package list.
```
apt update
```

Install PostgreSQL and its extra tools.

apt install -y postgresql postgresql-contrib

Check that it is running.
```
systemctl status postgresql
```
Switch to the special postgres user. The install creates this user to manage the database.
```
su - postgres
```
Open the Postgres command window.
```
psql
```
The prompt changes to postgres=#.

Create a new database user. Change the name and password.

CREATE USER myuser WITH PASSWORD 'choose-a-strong-password';

Create a database owned by that user.
```
CREATE DATABASE mydb OWNER myuser;
```
Leave the command window.
```
\q
```
Go back to the root user.
```
exit
```
Test the new login.
```
psql -h 127.0.0.1 -U myuser -d mydb
```
Type the password when asked. If you see the mydb=> prompt, it works.

Useful facts

Postgres uses port 5432. A port is like a numbered door into your server.
By default it only listens on the server itself. This is the safe choice.
On Ubuntu 18.04, the version installed is 10.
Settings live in /etc/postgresql/10/main/.

Warning: Do not open port 5432 to the whole internet. If a remote app needs access, allow only its IP address and take a backup first.

Quick recap

PostgreSQL is a free database.
Install it with apt install postgresql postgresql-contrib.
Use the postgres user and psql to create a user and a database.
Keep port 5432 private.