Re: pg_sequence_last_value() for unlogged sequences on standbys

On Wed, May 01, 2024 at 12:39:53PM +0900, Michael Paquier wrote:
> However, it seems to me that you should also drop the
> pg_is_other_temp_schema() in system_views.sql for the definition of
> pg_sequences. Doing that on HEAD now would be OK, but there's nothing
> urgent to it so it may be better done once v18 opens up. Note that
> pg_is_other_temp_schema() is only used for this sequence view, which
> is a nice cleanup.

IIUC this would cause other sessions' temporary sequences to appear in the
view. Is that desirable?

> By the way, shouldn't we also change the function to return NULL for a
> failed permission check? It would be possible to remove the
> has_sequence_privilege() as well, thanks to that, and a duplication
> between the code and the function view. I've been looking around a
> bit, noticing one use of this function in check_pgactivity (nagios
> agent), and its query also has a has_sequence_privilege() so returning
> NULL would simplify its definition in the long-run. I'd suspect other
> monitoring queries to do something similar to bypass permission
> errors.

I'm okay with that, but it would be v18 material that I'd track separately
from the back-patchable fix proposed in this thread.

--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com