Re: pg_decode_message vs skip_empty_xacts and xact_wrote_changes

On Mon, Jun 26, 2023 at 3:07 PM Ashutosh Bapat
<ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
>
> Hi All,
> Every pg_decode routine except pg_decode_message that decodes a
> transactional change, has following block
> /* output BEGIN if we haven't yet */
> if (data->skip_empty_xacts && !txndata->xact_wrote_changes)
> {
> pg_output_begin(ctx, data, txn, false);
> }
> txndata->xact_wrote_changes = true;
>
> But pg_decode_message() doesn't call pg_output_begin(). If a WAL
> message is the first change in the transaction, it won't have a BEGIN
> before it. That looks like a bug. Why is pg_decode_message()
> exception?
>

I can't see a reason why we shouldn't have a similar check for
transactional messages. So, agreed this is a bug.

--
With Regards,
Amit Kapila.