Re: Convert from LATIN9 to UTF-8 / WAL Replication

On Wed, May 10, 2017 at 5:05 AM, Fabrízio de Royes Mello <
fabrizio(at)timbira(dot)com(dot)br> wrote:

>
> Em ter, 9 de mai de 2017 às 17:40, basti <mailinglist(at)unix-solution(dot)de>
> escreveu:
>
>> Hello,
>>
>> I must convert a Latin9 Pg-cluster (Version 9.1) in utf-8 with minimal
>> downtime, if possible.
>> My idea is to use WAL replication for that.
>> Is it usable for that or in other words, can WAL Replication handle
>> different encoding on master/slave?
>
>
> Short answer: no!
>
>
> Is there perhaps an other way to do that?
>
>
> I never tried it, but you can use some logical replication tool like Slony.
>
>
> Is it possible to use on Master Version 9.1 and on Slave 9.6 (it will
>> get the new master in the next step)?
>>
>>
> Unfortunately no because on 9.1 version we don't have support for logical
> replication yet. We start supporting it since 9.4 using pglogical
> extension. As I said before you should consider use one external
> replication tool like Slony to do this job.
>
>
In a scenario like this it might also be worth upgrading to 9.6 using
pg_upgrade while maintaining the latin9 encoding, and then do a second
migratino which changes the encoding from 9.6 w latin9 to 9.6 w utf8. That
way you can get access to the newer tools such as pglogical to help you do
that.

--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>