Re: Logical replication from PG v13 and below to PG v14 (devel version) is not working.

On Thu, Sep 24, 2020 at 6:33 PM Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
>
> Hi Amit,
>
> > Here, I think instead of using MySubscription->stream, we should use
> > server/walrecv version number as we used at one place in tablesync.c.
>
> Should subscribers be setting the LR protocol value based on what is
> the publisher version it is communicating with or should it be set
> based on whether streaming was enabled or not while creating that
> subscription? AFAIU if we set this value based on the publisher
> version (which is lets say >= 14), then it's quite possible that the
> subscriber will start streaming changes for the in-progress
> transactions even if the streaming was disabled while creating the
> subscription, won't it?
>

No that won't happen because we send this option to the server
(publisher in this case) only when version is >=14 and user has
specified this option. See the below check in function
libpqrcv_startstreaming()
{
..
if (options->proto.logical.streaming &&
PQserverVersion(conn->streamConn) >= 140000)
appendStringInfo(&cmd, ", streaming 'on'");
..
}

--
With Regards,
Amit Kapila.