A “could not translate hostname to address” error occurs when you use the wrong DNS hostname or there are underlying problems with DNS resolution. The full error message may look like this:
psql: could not translate host name "cluster-do-user-1234567-0.db.ondigitalocean.com"
to address: Name or service not known
If you are getting this error, first verify that you are using the correct hostname to connect by following How to Connect to PostgreSQL Database Clusters. Then, verify whether the machine you’re connecting from has problems with DNS resolution by following Why does my domain fail to resolve?
To get started with DNS, see our community tutorial series, An Introduction to Managing DNS, and Retrieve DNS Information with dig.