Re: Back-out V10 upgrade but keep new data

Yeah, time spent in testing is always time well spent. Same, I've never had
to rollback to a previous PG version, but one thing to take in
consideration is the use of certain extensions, like PostGIS, usually you
need to upgrade them as well, and make sure that nothing breaks if your
application relies on them.

On Wed, Jan 23, 2019 at 4:03 PM Sonnenberg-Carstens, Stefan <
ssonnenberg(at)ophardt(dot)com> wrote:

> Hi,
>
>
>
> no, this won’t work.
>
> The parameters passed to statements are missing there.
>
>
>
> I thinks the easiest thing to do is pg_dump at the PG 10 regularly and
> feed it into PG 9 if it becomes necessary.
>
> Perhaps you need to tweak a few statements, but that should be simple.
>
>
>
> Provided that the database is not too big and you don’t require PITR or
> something.
>
> Then I also would opt for something different, perhaps slony.
>
>
>
> Cheers
>
>
>
> P.S.: Why would that happen? If you are able to import the database dump
> without errors, and your application is
>
> compatible (and all of what it required like jdbc, odbc, psycopg2 …) then
> why do you think something should
>
> come up out of nothing? Perhaps you should invest in testing beforehand.
>
> I did 4 upgrades in 2018 and never had to go back.
>
>
>
> *Von:* Rene Romero Benavides [mailto:rene(dot)romero(dot)b(at)gmail(dot)com]
> *Gesendet:* Mittwoch, 23. Januar 2019 22:38
> *An:* Rossi, Maria
> *Cc:* pgsql-sql(at)lists(dot)postgresql(dot)org
> *Betreff:* Re: Back-out V10 upgrade but keep new data
>
>
>
> In theory it could work, but I think that's error prone, you'd need to
> parse statements and their parameters, and concurrency could play a role in
> data consistency depending on your transaction isolation levels, etc. If
> any of the statements fails for whatever reason, you can't just skip them
> if you are to guarantee consistency, pgpool works by doing what you suggest
> but all PG versions must be the same.
>
> What's your average dml transaction volume ?
>
>
>
>
>
>
>
> On Wed, Jan 23, 2019 at 1:51 PM Rossi, Maria <maria(dot)rossi(at)jackson(dot)com>
> wrote:
>
> Also, if we set the *log_statement = ‘all’*, can I extract those
> statements and run against the restored V9.3 database?
>
> What do you think? Would that work?
>
>
>
> Thanks.
>
>
>
> Maria
>
>
>
>
>
> *From:* Rene Romero Benavides <rene(dot)romero(dot)b(at)gmail(dot)com>
> *Sent:* Wednesday, January 23, 2019 2:12 PM
> *To:* Rossi, Maria <maria(dot)rossi(at)jackson(dot)com>
> *Cc:* pgsql-sql(at)lists(dot)postgresql(dot)org
> *Subject:* Re: Back-out V10 upgrade but keep new data
>
>
>
> *EXTERNAL EMAIL*
>
> Check this out for CDC, haven't used it myself but I'm looking forward.
>
> https://debezium.io/
>
>
>
> On Wed, Jan 23, 2019 at 1:06 PM Rossi, Maria <maria(dot)rossi(at)jackson(dot)com>
> wrote:
>
> Hi,
>
>
>
> If I upgrade Postgres from V9.3 to V10, then need to roll-back to V9.3
> after data been entered, is there a way for me to save the new data so that
> I can re-apply it to the V9.3? After I restore my V9.3 backup, can I
> simply replay the V10 log unto V9.3? What are my options, if any?
>
>
>
> Thanks.
>
> Maria
>
>
>
>
>
>
> --
>
> El genio es 1% inspiración y 99% transpiración.
> Thomas Alva Edison
> http://pglearn.blogspot.mx/
>
>
>
>
>
>
> --
>
> El genio es 1% inspiración y 99% transpiración.
> Thomas Alva Edison
> http://pglearn.blogspot.mx/
>
>
>

--
El genio es 1% inspiración y 99% transpiración.
Thomas Alva Edison
http://pglearn.blogspot.mx/