Re: Uber migrated from Postgres to MySQL

On Fri, Jul 29, 2016 at 03:03:46PM -0400, D'Arcy J.M. Cain wrote:
> As does NetBSD.  The problem is that unlike Python (which BSD allows
> multiple versions) there is only one executable to deal with.  It's not
> an insurmountable problem but it could get messy.
>
> The answer is either chroot or mount and run pg_upgrade on another
> server. If you can afford the downtime you can also delete PG, install
> the new version and run pg_upgrade without modifying the existing DB.
> If it succeeds then replace the directories and restart the new
> version.  If it fails then uninstall PG, reinstall the older version
> and restart. Lather, rinse, repeat until it upgrades cleanly.

pg_upgrade needs to run the old and new server binaries as part of its
operation, so that would not work.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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