Re: Uber migrated from Postgres to MySQL

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.

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

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