Completely uninstall PostgreSQL 9.0.4 from Mac OSX Lion?

The following is the un-installation for PostgreSQL 9.1 installed using the EnterpriseDB installer. You most probably have to replace folder /9.1/ with your version number. If /Library/Postgresql/ doesn’t exist then you probably installed PostgreSQL with a different method like homebrew or Postgres.app.

To remove the EnterpriseDB One-Click install of PostgreSQL 9.1:

1. Open a terminal window. Terminal is found in: Applications->Utilities->Terminal

2. Run the uninstaller:

   sudo /Library/PostgreSQL/9.1/uninstall-postgresql.app/Contents/MacOS/installbuilder.sh
   

   If you installed with the Postgres Installer, you can do:

   open /Library/PostgreSQL/9.2/uninstall-postgresql.app
   

   It will ask for the administrator password and run the uninstaller.

3. Remove the PostgreSQL and data folders. The Wizard will notify you that these were not removed.

   sudo rm -rf /Library/PostgreSQL
   

4. Remove the ini file:

   sudo rm /etc/postgres-reg.ini
   

5. Remove the PostgreSQL user using System Preferences -> Users & Groups.

   1. Unlock the settings panel by clicking on the padlock and entering your password.
   2. Select the PostgreSQL user and click on the minus button.

6. Restore your shared memory settings:

   sudo rm /etc/sysctl.conf
   

That should be all! The uninstall wizard would have removed all icons and start-up applications files so you don’t have to worry about those.