Thread

Re: BUG #16961: Could not access status of transaction

Daniil Davydov <3danissimo@gmail.com> — 2025-08-06T03:30:39Z

Hi,

On Wed, Aug 6, 2025 at 6:30 AM Alexandra Wang
<alexandra.wang.oss@gmail.com> wrote:
>
> Thank you for sharing your interim solution! Inspired by your solution, I found
> that there is an existing built-in function "pg_notification_queue_usage()"[1]
>
>> pg_notification_queue_usage () → double precision
>> Returns the fraction (0–1) of the asynchronous notification queue's maximum
>> size that is currently occupied by notifications that are waiting to be
>> processed. See LISTEN and NOTIFY for more information.
>
>
> This function calls asyncQueueAdvanceTail(). I think it's a similar workaround
> to your patch, but without code change.
>
> What do you think?
>

Yep, it can be used as a workaround. But obviously the user doesn't know when
this function should be called - it will become clear only when an error occurs,
that is, post factum. Thus, I think that it is better to add such a
functionality
to the autovacuum. This simple code will ensure that there are no
errors in most cases.

--
Best regards,
Daniil Davydov