First Meeting with Postgres

I had to uninstall Postgres as I forgot the password for default admin user "postgres". What stupid I am. It really makes things difficult. So I have to uninstall the postgres. OK, another bad thing I made is I installed postgres by EnterpriseDB installer. It's always not an easy way to uninstall stuff that was not installed by homebrew. Fortunately, I found the following way to uninstall the postgres:
http://stackoverflow.com/questions/8037729/completely-uninstall-postgresql-9-0-4-from-mac-osx-lion

After the uninstallation, I installed postgres by homebrew:
$brew update
$brew install postgres

OK, now I've installed postgres successfully. It's time to lauch the postgres server by:
$pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
and check it is running:

$ps aux | grep postgres

Everything works as expected, and I tried to run rails but got an error:

FATAL:  role "dashboard" does not exist

It seems that I don't have that role created in postgres. Not a problem, it's easy to create a role by:

$createuser -P dashboard

Log into postgres and check the role:

$psql -d postgres -U [login user name]

postgres=# SELECT rolname FROM pg_roles;

       rolname       

---------------------

... 

dashboard

Good! The role "dashboard" has been created successfully. Now try rails again. What? another error again?
PG::InsufficientPrivilege: ERROR:  permission denied to create database
Looks like the role "dashboard" doesn't have the permission to create database. Check the permission for "dashboard" in postgres:
postgres=# \du
                                 List of roles
     Role name      |                   Attributes                   | Member of
---------------------+------------------------------------------------+----------
dashboard |                                                | {}

Yeah, no permission at all for "dashboard". Grant it appropriate permission:
postgres=# ALTER ROLE dashboard CREATEROLE CREATEDB;

Now, run the rails again. Sigh...another error again:
"dashboard_development" does not exist

I see. It's most likely because I didn't do db:create and db:migrate. So, let me do it:

$bundle exec rake db:create db:migrate

Well, finally the website is up and running!