Postgresql 9.4

Create the file /etc/apt/sources.list.d/pgdg.list, and add a line for the repository:

deb http://apt.postgresql.org/pub/repos/apt/ xenial-pgdg main

Import the repository signing key, and update the package lists:

wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update 

Then do:

sudo apt-get install postgresql-client-9.4 postgresql-9.4 postgresql-contrib-9.4 libpq-dev postgresql-server-dev-9.4

# pgAdmin III graphical administration utility
sudo apt-get install pgadmin3