Re: Decoupling antiwraparound autovacuum from special rules around auto cancellation

On Fri, 2022-10-21 at 17:39 -0700, Peter Geoghegan wrote:
> One small thought on the presentation/docs side of this: maybe it
> would be better to invent a new kind of autovacuum

It's possible this would be easier for users to understand: one process
that does cleanup work over time in a way that minimizes interference;
and another process that activates in more urgent situations (perhaps
due to misconfiguration of the first process).

But we should be careful that we don't end up with more confusion. For
something like that to work, we'd probably want the second process to
not be configurable at all, and we'd want it to be issuing WARNINGs
pointing to what might be misconfigured, and otherwise just be
invisible.

> That way we wouldn't be fighting against the widely held perception
> that antiwraparound autovacuums are scary.

There's certainly a terminology problem there. Just to brainstorm on
some new names, we might want to call it something like "xid
reclamation" or "xid horizon advancement".

When it starts to run out, we can use words like "wraparound" or
"exhaustion".

--
Jeff Davis
PostgreSQL Contributor Team - AWS