After upgrading everything in Homebrew, I discovered that my PostgreSQL no longer loaded, due to the database files being an older version than the PostgreSQL software. These are the steps I followed to upgrade all databases, and get up and running again.
1: Make sure PostgreSQL is not running before starting the upgrade process.
2: Make a new PostgreSQL 9.6 database where your old data will be migrated to.
3: Upgrade databases to 9.6 by using
pg_upgrade tool. To find the version number of the
old binaries, you simply
Change the version numbers needed for your setup, usage of the pg_upgrade tool is as simple as:
4: Move your new database to the PostgreSQL default location:
5: That’s it :)