postgres
brew install postgres
initdb /usr/local/var/postgres
Or start manually with:
pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
And stop with:
pg_ctl -D /usr/local/var/postgres stop -s -m fast
If you want to install the postgres gem, including ARCHFLAGS is recommended:
env ARCHFLAGS="-arch x86_64" gem install postgres