I want to upgrade my PostgreSQL 9.4 cluster to PostgreSQL 9.6 since upgrading debian to 9.0 (stretch) I lost PostgreSQL 9.4 however and it's also not in the repos anymore.
Without PostgreSQL 9.4 I however can't upgrade using pg_upgradecluster
Shall I install PostgreSQL 9.4 using an installer? Will it work on Debian stretch? Can I copy my cluster to a machine with Debian 8 and both versions of PostgreSQL to upgrade on?