Install PostgreSQL in Ubuntu 14.04

In Ubuntu 14.04, PostgreSQL repository isn't listed by default. We must add the record first.

Run $ nano /etc/apt/sources.list.d/pgdg.list to add repository list file
Add deb http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main in the file
Run $ wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | \
sudo apt-key add -
Run $ sudo apt-get update then $ sudo apt-get install postgresql-9.4

For administrator we can install pgadmin3
$ sudo apt-get install pgadmin3

For client tools we can install postgresql-client
$ sudo apt-get install postgresql-client

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