Does the Discourse install set a default postgres password?

I had the same question. Is there a password, if so, where is this in the configuration?

Is it safe to change the psql user password (e.g. password rotation) and where should the corresponding password be updated in the config?

If running python scripts against a database, it would be helpful to use the same password, otherwise the yml files need to be modified to create a separate database user and password and grant permissions.