Re: Uber migrated from Postgres to MySQL

On Wed, Jul 27, 2016 at 9:22 AM, Scott Mead <scottm(at)openscg(dot)com> wrote:
> On Wed, Jul 27, 2016 at 3:34 AM, Achilleas Mantzios <achill(at)matrix(dot)gatewaynet(dot)com> wrote:

>> Our last 1TB upgrade from 9.0 -> 9.3 went like a charm in something like
>> seconds. (with the -k option)
>> However, be warned that the planing and testing took one full week.

Agreed -- you should spend a lot more time on planning and testing
than the actual upgrade will take; but that will probably be true
with any product.

> That being said, it doesn't really provide a back-out plan.

Until you get to the end of the upgrade and *start the cluster
under the new version* you can fall back to the old version. I
remember a couple times that we saw something during a pg_upgrade
--link run that we weren't expecting, and did exactly that so we
could investigate and try again later.

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company