Re: Uber migrated from Postgres to MySQL

On 28.07.2016 17:50, Rakesh Kumar wrote:
> On Thu, Jul 28, 2016 at 10:38 AM, Alex Ignatov <a.ignatov@postgrespro.ru> wrote:
>
>> Sorry, what? You can rollback to previous version of software what you had.
>>
>> https://docs.oracle.com/cd/E11882_01/server.112/e23633/downgrade.htm#UPGRD007
> Not so fast. This requires the db to be set in compatibility mode of
> the lower version. Once that is removed, no downgrade is possible.
>
> Also starting from Oracle 12 this downgrade option has been removed.
> That is, you can't upgrade in-place from Or 11 to 12 and then
> downgrade back. The only supported way is the restore from an old
> backup (which is true  for all products). I don't work in Oracle, but
> got this clarified by someone who is an Oracle dba.
>
>

Not true -

https://docs.oracle.com/database/121/UPGRD/downgrade.htm#UPGRD007

About compatible params you are right but downgrade is possible from 12c.

Alex Ignatov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company