Installing postgresql on mac (mountain lion, if that matters)

install.sh

# install Homebrew (figure it out yourself)

#use brew to install postgresql

brew install postgresql

# Next, try and run the executable for postgresql command

psql

# If you get an error saying 'command not found' then that means that your executable path has not been set to your terminal.
# In ubuntu, you might need to edit bashrc file but in Mac its ~/.bash_profile wherein you set the path of the executable
# Once you have installed postgresql using Homebrew, the executable has also been setup in the Postgresql installed folder. One way is to browse through the folder
# the other is to use the 'find' command in terminal

sudo find / -name psql

# Add the path to the bash_profile

export PATH="/usr/local/bin:/usr/local/sbin:/usr/local/Cellar/postgresql/9.2.3/bin/:~/bin:$PATH"

# now you gotta run the initdb command

initdb /usr/local/var/postgres -E utf8

# There are chances that you might run into Shared segment errors for lack of memory. In that case, you can edit /etc/sysctl.conf file.
# Change it to this. (if the file does not exist, then create one)

kern.sysv.shmmax=1610612736
kern.sysv.shmmin=1
kern.sysv.shmmni=256
kern.sysv.shmseg=64
kern.sysv.shmall=393216

# Save and reboot and run the initdb command again

# Open the terminal again and try and run psql command

psql

# if you get an error like this :

database your-username does not exist

# then try this

psql -d postgres

# Once you are in psql shell, create a database by your username

create database your-username;

# Now quit 

\q

# Now try installing pg gem

gem install pg

# if you create a database with rake db:create command then chances are you might get this error

Library not loaded: /usr/local/opt/postgresql/lib/libpq.5.5.dylib

# So just find the libpq.5.5.dylib

sudo find / -name libpq.5.5.dylib

# copy the location of the file (it has to be present somewhere for sure)

# now just create a symlink for the libpq.5.5.dylib for the location that rails desires

sudo ln -s rails/desired/location location/of/libpq.5.5.dylib

# Do not forget to install instrumentation for pgAdmin

psql -d postgres < /usr/local/Cellar/postgresql/9.0.1/share/contrib/adminpack.sql

# 9.2.3 the location has changed to 

psql -d postgres < /usr/local/Cellar/postgresql/9.2.3/share/postgresql/extension/adminpack--1.0.sql

# thats about it !!

# this should work

# REf

# http://rails3hub.blogspot.in/2012/02/install-postgresql-9-on-os-x.html (Read the comments too)