I installed PostgreSQL via the graphical install on http://www.postgresql.org/download/macosx/
I see it in my applications and also have the psql terminal in my applicat
As a postgreSQL newbie I found the os x setup instructions on the postgresql site impenetrable. I got all kinds of errors. Fortunately the uninstaller worked fine.
cd /Library/PostgreSQL/11; open uninstall-postgresql.app/
Then I started over with a brew install followed by this article How to setup PostgreSQL on MacOS
It works fine now.