Re: Uber migrated from Postgres to MySQL

On Wed, Jul 27, 2016 at 12:59:59PM -0400, Bruce Momjian wrote:
> On Wed, Jul 27, 2016 at 12:47:24PM -0400, Bruce Momjian wrote:
> > On Wed, Jul 27, 2016 at 12:33:27PM -0400, Rakesh Kumar wrote:
> > > On Wed, Jul 27, 2016 at 11:45 AM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > >
> > > > I agree, but I am not sure how to improve it. The big complaint I have
> > > > heard is that once you upgrade and open up writes on the upgraded
> > > > server, you can't re-apply those writes to the old server if you need to
> > > > fall back to the old server. I also don't see how to improve that either.
> > >
> > > doesn't and pg_logical solve this by logically replicating and allowing for
> > > different architecture/version between the replication nodes ?
> >
> > Yes. I was saying I don't know how to improve pg_upgrade to address it.
>
> I think long-term we are looking at pg_logical for zero-downtime
> upgrades and _downgrades_, and pg_upgrade for less overhead (I don't
> want to make a second copy of my data) upgrades (but not downgrades).
>
> I think this is probably the best we are going to be able to do for a
> long time.

Oh, let me give credit to Simon, who has always seen pg_logical as
providing superior upgrade options where the logical replication setup
isn't a problem.

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

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