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Install PostgreSQL 9.2 on OS X Mountain Lion


The PostgreSQL database keeps getting better with each release. With 9.2 now at beta2, it's a great time to jump in and get up to speed.


This guide assumes the following:

  • OS X Mountain Lion
  • The latest XCode
  • XCode Command Line Tools
  • The latest MacPorts


Make sure MacPorts is up to date, then install the postgresql92-server port:

$ sudo port -v selfupdate
$ sudo port -v install postgresql92-server

Setup the Initial Database

Once the server has been installed, you will need to create the initial database:

$ sudo mkdir -p /opt/local/var/db/postgresql92/defaultdb
$ sudo chown postgres:postgres /opt/local/var/db/postgresql92/defaultdb
$ sudo su postgres -c '/opt/local/lib/postgresql92/bin/initdb -D /opt/local/var/db/postgresql92/defaultdb'

Starting the Server

Once the initial database has been created, you can start the server.

To run the server manually, execute the following command:

$ sudo su postgres -c '/opt/local/lib/postgresql92/bin/postgres -D /opt/local/var/db/postgresql92/defaultdb'

If you want the server to automatically start at boot time, execute the following command:

$ sudo launchctl load -w /Library/LaunchDaemons/org.macports.postgresql92-server.plist

Setup your PATH

The executable files for PostgreSQL are in a non-standard location, so you you'll want to update your PATH to make things easier. Most likely, you'll want to edit your ~/.bashrc or ~/.zshrc (or similar) profile, though you can set apply the changes for all users system-wide by editing /etc/profile.

Make sure you set the new path before /usr/bin to ensure that you are using the latest versions and not the default apple-supplied tools:

export PATH=/opt/local/lib/postgresql92/bin:$PATH

You can verify this works by running which psql and you should see /opt/local/lib/postgresql92/bin/psql as the output.

Create a New User

You will be setup with a postgres user by default, but it is good practice to create a different user account.

To make things easy, create a new database user to match your OS X username:

$ createuser --superuser <my username> -U postgres

You should now be able to create a new database:

$ createdb my_app

Do please consider setting a password for your newly-created user ;)

Configuring a Rails Application

To setup your Rails application with PostgreSQL, you will need to do the following:

  • Add the pg gem to your Gemfile and run the bundle command Gist
  • Configure your database.yml to use PostgreSQL: Gist

Even if you have set the min_messages option, you may still see console output like the following:

WARNING:  there is already a transaction in progress

Edit the file /opt/local/var/db/postgresql92/defaultdb/postgresql.conf and set the following:

client_min_messages = error

Everything should now be running smoothly.


  • Userpic

    Macports in 2012? Really? And I thought everyone switched to homebrew back in 2011.

  • Blank-mugshot

    @rwz, yep, really. MacPorts works, well and reliably. It also supports a lot of functionality which I use that homebrew doesn't support (activating/deactivating multiple versions for testing libraries, for example). Homebrew is great, and I recommend it often for many folks, but I need a better reason than "everyone else is doing it" to make the move myself.

    Thanks for the input!

  • Blank-mugshot

    A handy command is

    sudo port select --set postgresql postgresql92

    That way you you can type 'psql' instead of 'psql92', and so on for the other CLI tools.

  • U1b6bd8ad071161fb5bd43535867f4590

    Thanks bro! You saved my day.

  • Blank-mugshot

    @jfsagasti I'm glad you found it useful, thanks!

  • Blank-mugshot

    @apsoto, very nice addition, thank you!

  • Blank-mugshot

    @phlipper afaik brew also allows to use different versions of a package, after all it's a git wrapper. It may not be intuitive, but there's a way to get to all branches and commits in a package repo. Still it's a shame macports and homebrew don't work together.

  • Blank-mugshot

    @ellmo sure it's technically possible, but have you seen this done in practice? I don't think this would account for related dependencies. Can you link to some documentation on how to do this?

    Once brew is as easy as port activate name @version I'll definitely take a closer look.

  • A5853d85-557d-4a8f-9639-197b5b2a449d_normal

    NIce post thanks for the help!!

  • Blank-mugshot

    @chrisdilbert I'm glad you found it useful, thanks!

  • Blank-mugshot

    Or you can try this: http://postgresapp.com

  • Blank-mugshot

    this post saved my day. thanks.

  • Blank-mugshot

    As written, your initdb command sets the default encoding to SQL-ANSI. To set the default as UTF8, you need to do this, instead:

    sudo su postgres -c '/opt/local/lib/postgresql92/bin/initdb -E UTF8 -D /opt/local/var/db/postgresql92/defaultdb'

    Note: The above command is supposed to be on one line. Also, the order of the parameters is important. The encoding must come before the location of the database files. This is also true for postgreSQL93, which is what I actually installed.

  • Blank-mugshot

    I have a serious question I can't seem to find an answer to. Everywhere I go people just use "port (command input)" but on the website they say to do "sudo port (command input)" I haven't been able to execute any port commands without doing sudo first. Are you doing sudo before everything and assuming we do that or do you have a special configuration for it?

  • Blank-mugshot

    @to-mos, FWIW I've generally used sudo when working with the port command.

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