Re: A Modest Upgrade Proposal

On Thu, Jul 28, 2016 at 09:22:17AM +0800, Craig Ringer wrote:
> It might, actually. One approach for online upgrade is to:
>
> * pg_basebackup the master
> * start the replica and let it catch up
> * create a logical replication slot on the master
> * replace the replication.conf on the basebackup so it stops recovery at the
> lsn of the replication slot's confirmed_flush_lsn
> * stop the replica and pg_upgrade it
> * have the upgraded replica, now a master, replay from the old master over
> logical replication
> * once caught up, switch over
>
> This means a full dump and reload with a full rebuild of all indexes, etc,
> isn't needed. All shared catalog stuff is copied (until we switch to logical
> rep for the final catch-up).

Right, using pg_upgrade as part of a logical upgrade procedure makes
sense. I was referring to having pg_upgrade --online do all of those
bullets plus what is does now --- that just seems like it would fail as
too complex, and if someone wanted to do just pg_upgrade without the
logical, the manual page would be incomprehensible.

In summary, I think we need to keep pg_upgrade doing what it does well,
and come up with another tool that does those bullets. Heck, people
already can't find --link.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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