PostgreSQL

Before you can use PostgreSQL you need to install it. It is possible that PostgreSQL is already installed in the system, either because it was included in your operating system distribution or because the system administrator already installed it.

To verify if PostgreSQL is already installed, run the following command in the Terminal window:

systemctl status postgresql

The expected response when PostgreSQL is:

• Installed: Active: active

• Not installed: Unit postgresql.service could not be found

If PostgreSQL is not already available, you can install it yourself. This does not require superuser (root) access.

PostgreSQL is available as binary packages for most common operating systems. This is the recommended way to install PostgreSQL. For an updated list of platforms providing binary packages, please visit the Download section on the PostgreSQL website at PostgreSQL: Downloads and follow the instructions for your specific platform.

Note: This section explains how to install PostgreSQL on a Linux machine running Ubuntu.

1. Open the Terminal window on your machine.

2. Enter the following commands:

     sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
     wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
     sudo apt-get update
     sudo apt-get -y install postgresql
   

   This installs the PostgreSQL server on your machine and creates a postgres user.

A database cluster is a single directory where all your data is stored. You can choose the location of the directory.

Perform the following steps to create (initialize) the database cluster:

1. Log in to your PostgreSQL server as the postgres user created in step 1.

2. Enter the following command to create the database cluster. The -D option allows you to specify where the database cluster should be stored.

   $ initdb -D /usr/local/pgsql/data
   

Note: The initdb command attempts to create the directory you specify if it does not already exist. This fails if initdb does not have permissions to write in the parent directory. It is recommended that the PostgreSQL user own not just the data directory but its parent directory as well. If the desired parent directory does not exist, you need to create it first, using root privileges. To do this, enter the following commands:

root# mkdir /usr/local/pgsql
root# chown postgres /usr/local/pgsql
root# su postgres 4$ initdb -D /usr/local/pgsql/data

When a cluster is created, a database named postgres is created by default, which is used by utilities, users, and third-party applications. You can use this database instance to set up the Destination.