Horton

Re: Converting WAL to SQL

Julien Rouhaud <rjuju123@gmail.com>

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From: Julien Rouhaud <rjuju123@gmail.com>
To: Bruce Momjian <bruce@momjian.us>
Cc: Fabrízio de Royes Mello <fabriziomello@gmail.com>, Michael Paquier <michael@paquier.xyz>, rajesh singarapu <rajesh.rs0541@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-01-05T17:19:35Z
Lists: pgsql-hackers 
On Thu, Jan 6, 2022 at 12:19 AM Bruce Momjian <bruce@momjian.us> wrote:
>
> On Tue, Jan  4, 2022 at 10:47:47AM -0300, Fabrízio de Royes Mello wrote:
> >
> >
> > What we did was decode the 9.6 wal files and apply transactions to the
> > old 9.2 to keep it in sync with the new promoted version. This was our
> > "rollback" strategy if something went wrong with the new 9.6 version.
>
> How did you deal with the issue that SQL isn't granular enough (vs.
> row-level changes) to reproduce the result reliably, as outlined here?

This is a logical decoding plugin, so it's SQL containing decoded
row-level changes.  It will behave the same as a
publication/suscription (apart from being far less performant, due to
being plain SQL of course).