Postgres - FATAL: database files are incompatible with server
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-databaseThe above command is taken from the output of brew info postgres
If you are looking for the nuclear option (delete all data and get a fresh database), you can do:
rm -rf /usr/local/var/postgres && initdb /usr/local/var/postgres -E utf8
and then you'll need to rake db:setup and rake db:migrate from your Rails app to get setup again.
Try this : https://gist.github.com/joho/3735740
It worked perfectly for me.In the end it also generates you 2 bash scripts to check your DB and remove the old cluster.Really Awesome.
see: http://www.postgresql.org/docs/9.2/static/pgupgrade.html to understand more.