On Fri, Jul 29, 2016 at 02:50:32PM -0400, Stephen Frost wrote:
> > Er, using a not yet invented pg_downgrade:-)
>
> The short answer is 'no'. Consider a case like the GIN page changes- as
> soon as you execute DML on a column that has a GIN index on it, we're
> going to rewrite that page using a newer version of the page format and
> an older version of PG isn't going to understand it.
>
> Those kind of on-disk changes are, I suspect, why you have to set the
> "compatibility" option in the big $O product to be able to later do a
> downgrade.
Yes, you would need a mode that prevented new-format writes on the new
server.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
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