Re: archive status ".ready" files may be created too early

On 2021-Feb-19, Bossart, Nathan wrote:

> 0002 adds logic for persisting the last notified segment through
> crashes.  This is needed because a poorly-timed crash could otherwise
> cause us to skip marking segments as ready-for-archival altogether.
> This file is only used for primary servers, as there exists a separate
> code path for marking segments as ready-for-archive for standbys.

I'm not sure I understand what's the reason not to store this value in
pg_control; I feel like I'm missing something.  Can you please explain?

There were some comments earlier in the thread about the maximum size of
a record.  As I recall, you can have records of arbitrary size if you
have COMMIT with a large number of relation invalidation messages being
included in the xlog record, or a large number of XIDs of
subtransactions in the transaction.  Spanning several segments is
possible, AFAIU.

-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/
"La rebeldía es la virtud original del hombre" (Arthur Schopenhauer)