Re: Track in pg_replication_slots the reason why slots conflict?

On Thu, Dec 21, 2023 at 5:51 AM Michael Paquier <michael@paquier.xyz> wrote:
>
> While listening at Bertrand's talk about logical decoding on standbys
> last week at Prague, I got surprised by the fact that we do not
> reflect in the catalogs the reason why a conflict happened for a slot.
> There are three of them depending on ReplicationSlotInvalidationCause:
> - WAL removed.
> - Invalid horizon.
> - Insufficient WAL level.
>

The invalidation cause is also required by one of the features being
discussed "Synchronize slots from primary to standby" [1] and there is
already a thread to discuss the same [2]. As that thread started
yesterday only, you may not have noticed it. Currently, the proposal
is to expose it via a function but we can extend it to also display
via view, feel free to share your opinion on that thread.

[1] - https://www.postgresql.org/message-id/514f6f2f-6833-4539-39f1-96cd1e011f23@enterprisedb.com
[2] -
https://www.postgresql.org/message-id/CAJpy0uBpr0ym12%2B0mXpjcRFA6N%3DanX%2BYk9aGU4EJhHNu%3DfWykQ%40mail.gmail.com

--
With Regards,
Amit Kapila.