Zahir Lalani <ZahirLalani@oliver.agency> writes: > We have done pg10 upgrades from 9.6 on all our environments successfully. We have an automation script that does this for us. One environment is a near replica of our production setup and all works fine. > We have now made 2 attempts at doing this on production - both ending up with rollback > The key issue we have is that all queries were incredibly slow. The PG 10 postmaster workers would all show 100% cpu, especially on the replicas. We even increased CPUs but that made no difference. Did you make sure to rebuild statistics (re-ANALYZE) after the upgrade? pg_upgrade makes a script for that, but I don't believe it runs it for you. regards, tom lane