Maria D. Campbell

How to uninstall postgreSQL on OSX and reinstall with Homebrew

May 1st, 2018

Earlier today I wrote a post about what happens when you migrate your data from an older macbook pro (mine was from late 2013) to a newer one (mine is from late 2016) with the OSX Migration Assistant.

In this post, I list the steps I took to uninstall postgreSQL installed from the postgreSQL website and reinstall it using Homebrew.

For those of you not familiar with it, Homebrew is the missing package manager for macOS. Created by developer Max Howell in 2009, Homebrew installs the stuff you need that Apple didn't.

I swear by it. So many other developers on OSX swear by it for so many different things. Today it saved me yet again.

These are the steps I took to uninstall my postgreSQL install from the postgreSQL website:

First I backed up my two postgreSQL installs, version 9.0.4 and version 10.3 to my external hard drive, JUST IN CASE.

  • I uninstalled postgreSQL with the postgreSQL uninstaller. Since I had inadvertently installed two versions of posgreSQL. version 9.0.4 and then version 10.3. I uninstalled both. The data directory remained after both uninstalls, so I manually removed both.

  • Then I had to make sure to remove all files and directories related to postreSQL before re-installing. So I checked to see if anything was left over by going into the following path in command line:

/usr/local/var/postgres
  • Then I did an ls -a to see if there was anything in there. There was, so I typed the following in command line:
rm -rf /usr/local/var/postgres
  • This removed everything within the postgres directory. Some take it a step further to remove all local traces of postgres (I did not because I had done an postgreSQL uninstall and then removed the data directory via GUI. I can’t vouch for this step since I did not do it.):
rm -rf .psql_history .psqlrc .psql.local .pgpass .psqlrc.local

To view the original source for this information, please visit Completely Uninstall and Reinstall PSQL on OSX by Bita Djaghouri.

  • Then I typed the following command to install postgreSQL with Homebrew:
brew install postgreSQL

In some places you may see brew install postgres. I went with the former.

  • Then, for the sake of ease and time saving, I started postgreSQL with Homebrew by typing the following command:
brew services start postgresql
  • If you restart PostgreSQL using Homebrew with this command, you will not have to restart Postgres services every time you want to run psql. It is a matter of preference.

  • Now comes the cool part. Instead of inheriting the default postgres db that comes with the GUI (Graphical User Interface) installation, you can create a customized one with your system username by typing the following command in Terminal/command line:

createdb `whoami`

exactly as shown, with back ticks and all.

  • whoami is actually a command you type in Terminal when you want to confirm what user you are in at any given time. By typing the above command, you are telling postgres to create your default database and name it with your username. In my case, it is mariacam, so my default database is mariacam instead of postgres.

  • Next I typed the following command:

psql

And this is what was returned in the Terminal console:

psql (10.3)
Type “help” for help.
mariacam=#
  • The last step was to make sure that my projects were connecting with the database they were associated with and that my code was working. That part is up to you!

Releated Resources:

Tagged in: osx command-line terminal homebrew full-stack-javascript postgresql web-development
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