>> 1/ We should emit a log when autovacuum_workers is set higher than the max.
>> Hm. Maybe the autovacuum launcher could do that.
Would it be better to use a GUC check_hook that compares the
new value with the max allowed values and emits a WARNING ?
autovacuum_max_workers already has a check_autovacuum_max_workers
check_hook, which can be repurposed for this.
In the POC patch, this check_hook is kept as-is, which will no longer make sense.
>> 2/ should the name of the restart limit be "reserved_autovacuum_workers"?
>> That's kind-of what I had in mind, although I think we might want to avoid
>> the word "reserved" because it sounds a bit like reserved_connections
>> and superuser_reserved_connections
Yes, I agree. This can be confusing.
>> "autovacuum_max_slots" or
>> "autovacuum_max_worker_slots" might be worth considering, too.
"autovacuum_max_worker_slots" is probably the best option because
we should have "worker" in the name of the GUC.
Regards,
Sami