Postgres: how to upgrade 9.3 to 9.4 in ubuntu 14.04

How to upgrade postgres 9.3 to 9.4 in ubuntu

1. Create file /etc/apt/sources.list.d/pgdg.list

Make /etc/apt/sources.list.d/pgdg.list and add a line below.

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

2. apt-get update

After saving pgdg.list, import repository signing key and update package list.

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

3. Install postgres 9.4

sudo apt-get install postgresql-9.4

Then check 9.4 version well

psql --version
psql (PostgreSQL) 9.4.17

For more information, check postgres official docs