Re: pg_upgrade and publication/subscription problem

On Fri, Nov 26, 2021 at 5:47 PM Marcos Pegoraro <marcos(at)f10(dot)com(dot)br> wrote:
>>
>> So, in short, I think what we need to solve is to get the data from
>> new tables and newly performed writes on old tables. I could think of
>> the following two approaches:
>>
>> Approach-1:
>> 1. Drop subscription and Truncate all tables corresponding to subscription.
>>
>> 2. Create a new subscription for the publication.
>
> If I drop subscription it will drop WAL ou publication side and I lost all changed data between the starting of pg_upgrade process and now.
>

On thinking about this point again, it is not clear to me why that
would matter for this particular use case? Basically, when you create
a new subscription, it should copy the entire existing data from the
table directly and then will decode changes from WAL. So, I think in
your case all the changes between pg_upgrade and now should be
directly copied from tables, so probably older WAL won't be required.

--
With Regards,
Amit Kapila.