Re: A new function to wait for the backend exit after termination

On Wed, Oct 28, 2020 at 7:51 PM David G. Johnston
<david.g.johnston@gmail.com> wrote:

> I was thinking this would be useful for orchestration.  However, as you say, its a pretty fragile method.  I withdraw the suggestion.
>

So, pg_wait_backend(pid, timeout) waits until the backend with a given
pid is terminated?

>
>What I would replace it with is a pg_wait_for_notify(payload_test) function that allows an SQL user to plug itself into the listen/notify feature and pause the session until a notification arrives.  The session it is coordinating with would >simply notify just before ending its script/transaction.
>

Why does one session need to listen and wait until another session
notifies? If my understanding is wrong, could you please elaborate on
the above point, the usage and the use case?