Step 1: Add PostgreSQL Apt Repository

PostgreSQL packages are also available in default Ubuntu repository, But when I try to install PostgreSQL on Ubuntu 12.04 I only found PostgreSQL 9.1 was in default apt repository. So I request you to add PostgreSQL apt repository first in your system suggested on official PostgreSQL.

$ sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ `lsb_release -cs`-pgdg main" >> /etc/apt/sources.list.d/pgdg.list'
$ wget -q https://www.postgresql.org/media/keys/ACCC4CF8.asc -O - | sudo apt-key add -

Step 2: Install PostgreSQL

Now as we have added PostgreSQL official repository in our system, First we need to update repository list. After that install Latest PostgreSQL Server in our Ubuntu system using following commands.

$ sudo apt-get update
$ sudo apt-get install postgresql postgresql-contrib

Step 3: Connect to PostgreSQL

After installing PostgreSQL database server, by default it creates a user ‘postgres’ with role ‘postgres’. It also creates a system account with same name ‘postgres’. So to connect to postgres server, login to your system as user postgres and connect database.

$ sudo su - postgres
$ psql

Now you are logged in to PostgreSQL database server. To check login info use following command from database command prompt.

postgres-# \conninfo

To disconnect from PostgreSQL database command prompt just type below command and press enter. It will return you back to Ubuntu command prompt.

postgres-# \q

Step 4: Install pgAdmin3

sudo apt-get install pgadmin3