Re: Wrong comment for ReplicationSlotCreate

Daniil Davydov <3danissimo@gmail.com>

From: Daniil Davydov <3danissimo@gmail.com>
To: Chao Li <li.evan.chao@gmail.com>
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-12-30T10:07:22Z
Lists: pgsql-hackers
Hi,

On Tue, Dec 30, 2025 at 4:18 PM Chao Li <li.evan.chao@gmail.com> wrote:
>
> But I think the updated version is too simple. It loses the information that enabling two_phase later can result in missing PREPARE.
>
> So, I would suggest something like:
> ```
> * two_phase: If enabled, allows decoding of prepared transactions.
> *     Note that enabling this option after decoding has already advanced
> *     may result in missing PREPARE records for transactions that were
> *     prepared before the option was enabled.
>
> ```

Thanks for the review!

As far as I understand, if the publisher prepares a transaction and
then subscriber
tries to create a subscription, walsender will wait until the prepared
transaction is
finished (during execution of  CREATE_REPLICATION_SLOT command).
We can find this logic inside the SnapBuildFindSnapshot function. Thus, we
cannot miss any PREPARE record for the created slot.

Am I missing something?

--
Best regards,
Daniil Davydov