Re: Allow pg_signal_backend members to use pg_log_backend_memory_stats().

On 10/23/21, 12:57 PM, "Jeff Davis" <pgsql(at)j-davis(dot)com> wrote:
> pg_signal_backend seems like the appropriate predefined role, because
> pg_log_backend_memory_contexts() is implemented by a sending signal.

This seems reasonable to me. The stated reason in the original commit
message for keeping it restricted to superusers is because of the
denial-of-service risk, but if you've got pg_signal_backend, you can
already terminate sessions. The predefined roles documentation notes
that members of pg_signal_backend cannot signal superuser-owned
backends, but AFAICT pg_log_backend_memory_contexts() has no such
restriction at the moment. Should we add this?

Otherwise, presumably we will need to update func.sgml and the comment
above pg_log_backend_memory_contexts() in mcxtfuncs.c.

This is unrelated to this patch, but should we also consider opening
up pg_reload_conf() and pg_rotate_logfile() to members of
pg_signal_backend? Those are the other "server signaling functions" I
see in the docs.

Nathan