Just dug into postgres documentation and couldn't get a clear answer on this. With Debian Jessie hitting EOL for Debian LTS in June, we are upgrading our database servers along with our other servers to Stretch. This brings postgres-9.6 into the limelight. We've successfully upgraded test server 9.4 clusters via pg_upgrade which the Debian apt package automatically triggers notifications about when it notices more than one postgres version during the big 'ol dist-upgrade. We employ continuous archiving and PITR via a cron job and the following method: https://www.postgresql.org/docs/9.6/continuous-archiving.html
My question is, would a PITR restore with a WAL segment made with the 9.4 cluster be restore-able into the 9.6 cluster that results from the upgrade? I'm a lowly software dev with a DevOps focus and I don't want to make our DBA's uncomfortable with a from-the-hip-upgrade that might break backup compatibility. What's everyone's experience?