PostgreSQL and Ubuntu install

List what is available in the enabled repositories on your Ubuntu install:
apt-cache search postgresql | grep -P "^postgresql-[0-9\.]+ "
Install the latest version:
R=$(lsb_release -c | perl -pe 's/.*\t//g')
echo "deb http://apt.postgresql.org/pub/repos/apt/ "$R"-pgdg main" > /etc/apt/sources.list.d/pgdg.list
apt-get install wget ca-certificates
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
apt-get update
apt-get upgrade
P=$(apt-cache search postgresql | grep -P "^postgresql-contrib-[0-9\.]+ " | sort | tail -n 2 | head -n 1 | perl -pe 's/ .*//g')
apt-get install $P
Directories of interest are:
conf /etc/postgresql/9.4/main/
data /var/lib/postgresql/9.4/main/base/