On Tue, Feb 9, 2021 at 4:59 PM Ashutosh Bapat
<ashutosh.bapat.oss@gmail.com> wrote:
> Can you please provide steps which can lead to this situation? If
> there is an earlier discussion which has example scenarios, please
> point us to the relevant thread.
>
> If we are not sending PREPARED transactions that's fine, but sending
> the same prepared transaction as many times as the WAL sender is
> restarted between sending prepare and commit prepared is a waste of
> network bandwidth. The wastage is proportional to the amount of
> changes in the transaction and number of such transactions themselves.
> Also this will cause performance degradation. So if we can avoid
> resending prepared transactions twice that will help.
One of this scenario is explained in the test case in
postgres/contrib/test_decoding/specs/twophase_snapshot.spec
regards,
Ajin Cherian
Fujitsu Australia