#Mongo

###Install

brew install mongo

###Run as process (not as service)

To have launchd start mongodb at login:
ln -sfv /usr/local/opt/mongodb/*.plist ~/Library/LaunchAgents

Then to load mongodb now:
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mongodb.plist

Or, if you don't want/need launchctl, you can just run:
mongod --config /usr/local/etc/mongod.conf

To run in background on Mac OS X use the --fork option
mongod --fork --config /usr/local/etc/mongod.conf

#MySQL

###Install

brew install mysql

###Run as a process (not as a service)

mysql.server start

mysql.server stop

#PostgreSQL

###Install psql --version brew install postgresql initdb /usr/local/var/postgres pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start which psql

###Run

 postgres -D /usr/local/var/postgres

###Run as service To have launchd start postgresql at login:

ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents

Then to load postgresql now:

launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

###Upgrading Postgresql installed via Homebrew

See this article: http://www.jontourage.com/2012/06/19/postgresql-9-upgrade/

###Postgresql via Homebrew + Yosemite

This Stackoverflow question solves the problem of Postgresql not starting under Yosemite