macos - Postgres - FATAL: database files are incompatible with server

Question

After restarting my MacBook Pro I am unable to start the database server:

could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

I checked the logs and the following line appears over and over again:

FATAL:  database files are incompatible with server
DETAIL:  The data directory was initialized by PostgreSQL version 9.2, which is not compatible with this version 9.0.4.

9.0.4 was the version that came preinstalled on the mac, 9.2[.4] is the version I installed via Homebrew. As mentioned, this used to work before the restart, so it can't actually be an compiling issue. I also re-ran initdb /usr/local/var/postgres -E utf8 and the file still exists.

Unfortunately, I am pretty new to Postgres, so any help would be very much appreciated.

Answer 1

If you recently upgraded to 11 or 12 from 10.x you can run the below command to upgrade your postgres data directory retaining all data:

brew postgresql-upgrade-database

The above command is taken from the output of brew info postgres