Introduction to PostgreSQL

Introduction

PostgreSQL is a powerful, open source object-relational database system that uses and extends the SQL language combined with many features that safely store and scale the most complicated data workloads.

📎 PostgreSQL Official Documentation

Unlike other RDBMSs (relational database management systems), PostgreSQL supports both relational and non-relational data types. This makes it one of the most compatible, stable, and mature relational databases available today.

📎 IMB. What is PostgreSQL

First Steps

Installation

To install PostgreSQL in a Linux-based system, you can download via official repositories (in case of Debian-based distributions):

Linux

Debian-Based Distributions

sudo apt install postgresql

Start

Now, when you install for first time, postgresql creates a user named "postgres", so to start postgresql you have to type in terminal

sudo -u postgres psql

Once you push enter, you will be seeing in your terminal the shell to use postgres:

First commands

Some basic commands learning to use the postgres shell:

# This command allows you to see all databases stored in postgres
\l 

# To exit from postgres
\q

Using postgres by first time, you will be aware that postgres user does not have a password, so we have to set one:

alter user <user-name> with password 'new_password'

# To this example it will be
alter user postgres with password 'password'

Now you will be able to connect remotely using password

Graphical Application

If you wish to use PostgreSQL using a graphical desktop application, you can install pgadmin via package:

Debian-based distributions

sudo apt-get install pgadmin