On Thu, Mar 31, 2022 at 10:11 AM Andres Freund <andres@anarazel.de> wrote:
> I don't think we should weaken defenses against xids from before relfrozenxid
> in vacuum / amcheck / .... If anything we should strengthen them.
>
> Isn't it also just plainly required for correctness? We'd not necessarily
> trigger a vacuum in time to remove the xid before approaching wraparound if we
> put in an xid before relfrozenxid? That happening in prune_xid is obviously
> les bad than on actual data, but still.
Yeah, you're right. Ambiguity about stuff like this should be avoided
on general principle.
> ISTM we should just use our own xid. Yes, it might delay cleanup a bit
> longer. But unless there's already crud on the page (with prune_xid already
> set, the abort of the speculative insertion isn't likely to make the
> difference?
Speculative insertion abort is pretty rare in the real world, I bet.
The speculative insertion precheck is very likely to work almost
always with real workloads.
--
Peter Geoghegan
