How do i setup PostgreSQL? I am following https://www.drupal.org/node/1438206, but i got stuck at Point 2. i.e Add the bin directory of postgres, /Library/PostgreSQL/8.4/bin to the PATH in your .bashrc file in your home directory. Remember to run ./.bashrc to update the path.

I installed postgreSQL using brew. Now i do not find /Library/PostgreSQL/*/bin path i.e I do not find PostgreSQL inside Library.
Also i do not find .bashrc file . 

I have installed postgreSQL for sure.Please help me out.
I highly, highly suggest not installing these things directly to the operating system. It will just be more problematic instead of using a contained, virtual environment.

Instead, I advise using virtual environments (Vagrant/Docker). I use DrupalVM for development. For PostgreSQL you can see this thread for info on how to get it up and going.

Here is a Docker flavored VM with instructions on PostgreSQL support.

The linked drupal.org page you mentioned is four years old. I wouldn't follow it.