Jan Nieuwenhuizen writes: > Hi! > > I reconfigured my system and pulled in the postgres 9.6.2 update. Now > postgres does not start, /var/log/messages has > > May 12 13:02:52 localhost postgres[451]: [1-1] FATAL: database files are > incompatible with server > May 12 13:02:52 localhost postgres[451]: [1-2] DETAIL: The data > directory was initialized by PostgreSQL version 9.5, which is not compatible > with this version 9.6.2. > > > I have reverted the postgres update and everything is "fine" again.s
I think database upgrades can be performed with 'pg_upgrade', which is included in the postgresql package. The command's '--help' switch even includes an example. In my experience (9.2 > 9.3, 9.3 > 9.4, 9.4 > 9.5), the upgrades went just fine. You have to stop the postgresql daemon, perform the upgrade, and start it again. > > How do we want to handle this? I imagine that postgres has some way to > update its database...and I probably can figure out how to do that. But > do our users need to know this? And more importantly, if I upgrade, > will I be able to revert to a previous generation of my system? I think providing the latest PostgreSQL software is OK.. If you want to stay on the previous version of PostgreSQL, stick to that package (e.g. don't upgrade). I don't think PostgreSQL upgrades are downgradeable. But you can keep the "old" data directory so that a downgrade will still work with the data in your database at the time before the upgrade. Hope this helps.. Kind regards, Roel Janssen
