PostgreSQL 9.3 to 9.4.1 upgrade steps

pg_upgrade.sh

# Steps to install and run PostgreSQL 9.4.1 using Homebrew (Mac OS X)
# (if you aren't using version 9.3, change line #9 with the correct version)

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
mv /usr/local/var/postgres /usr/local/var/postgres93
brew update
brew upgrade postgresql
initdb /usr/local/var/postgres -E utf8
pg_upgrade -b /usr/local/Cellar/postgresql/9.3/bin -B /usr/local/Cellar/postgresql/9.4.1/bin -d /usr/local/var/postgres93 -D /usr/local/var/postgres
cp /usr/local/Cellar/postgresql/9.4.1/homebrew.mxcl.postgresql.plist ~/Library/LaunchAgents/
pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

# If you're using ruby, also:

gem pristine pg