On Wed, Jul 18, 2012 at 09:36:51AM -0400, Robert Haas wrote: > On Tue, Jul 17, 2012 at 6:02 PM, Bruce Momjian <br...@momjian.us> wrote: > > However, I have two ideas. First, I don't know _why_ the > > primary/standby would be any different after pg_upgrade, so I added the > > documentation mention because I couldn't _guarantee_ they were the same. > > Actually, if people can test this, we might be able to say this is safe. > > > > Second, the user files (large) are certainly identical, it is only the > > system tables (small) that _might_ be different, so rsync'ing just those > > would add the guarantee, but I know of no easy way to rsync just the > > system tables. > > I'm scratching my head in confusion here. After pg_upgrade, the > master is a completely new cluster. The system catalog contents are > completely different, and so are things like the database system > identifier and the WAL position - yeah, the latter is approximately > the same, but almost doesn't count except in horseshoes. Obviously > any attempt to replay WAL from the new cluster on the old cluster is > doomed to failure, at least unless we do a bunch more engineering here > that hasn't really been thought about yet.
No, the point is they run pg_upgrade on the stopped primary and stopped standbys. Are those the same? I am not really sure. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers