Install postgresql 9.4 and configure it for Ruby on Rails

PostgreSQL is available in the default repositories. So enter the following command from the Terminal to install it.

sudo apt-get install postgresql postgresql-contrib

If you’re looking for other versions, add the PostgreSQL repository, and install it as shown below.

On Ubuntu 14.10 systems:
Create the file /etc/apt/sources.list.d/pgdg.list;

vi /etc/apt/sources.list.d/pgdg.list

Add a line for the repository:

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

On Ubuntu 14.04, add the following line:

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

On Ubuntu 12.04, add the following line:

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

Import the repository signing key:

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

Update the package lists:

sudo apt-get update

Then install the required version.

sudo apt-get install postgresql-9.4

Access PostgreSQL command prompt :

The default database name and database user are “postgres”. Switch to postgres user to perform postgresql related operations:

sudo -u postgres psql postgres

If this command is not work, you can use it –
sudo sudo -u postgres psql

Sample Output:

psql (9.4rc1)
Type "help" for help.

postgres=#

Now Create database –

postgres=# create database “cc_database”;

So a list of command in terminal is .
$ createuser ubuntu -dslP
$ Enter password for new role: **same password from your yaml file**
$ Enter it again:

You can test the user –

$ echo $USER

Set your yaml file like this

development:

adapter: postgresql

encoding: utf8

database: cc_database

pool: 5

username: ubuntu

password: password