Re: Perform streaming logical transactions by background workers and parallel apply

On Fri, Oct 28, 2022 at 3:04 PM shiy.fnst@fujitsu.com
<shiy.fnst@fujitsu.com> wrote:
>
> On Tue, Oct 25, 2022 2:56 PM Wang, Wei/王 威 <wangw.fnst@fujitsu.com> wrote:
>
> I tried to write a draft patch to force streaming every change instead of
> waiting until logical_decoding_work_mem is exceeded, which could help to test
> streaming parallel. Attach the patch. This is based on v41-0001 patch.
>

Thanks, I think this is quite useful for testing.

> With this patch, I saw a problem that the subscription option "origin" doesn't
> work when using streaming parallel. That's because when the parallel apply
> worker writing the WAL for the changes, replorigin_session_origin is
> InvalidRepOriginId. In current patch, origin can be active only in one process
> at-a-time.
>
> To fix it, maybe we need to remove this restriction, like what we did in the old
> version of patch.
>

Agreed, we need to allow using origins for writing all the changes by
the parallel worker.


--
With Regards,
Amit Kapila.