Simon Riggs <simon.riggs@enterprisedb.com> writes:
> On Tue, 22 Nov 2022 at 16:28, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> If we do those things, do we need a wasted-work counter at all?
> The wasted work counter works well to respond to heavy read-only
> traffic and also avoids wasted compressions for write-heavy workloads.
> So I still like it the best.
This argument presumes that maintenance of the counter is free,
which it surely is not. I don't know how bad contention on that
atomically-updated variable could get, but it seems like it could
be an issue when lots of processes are acquiring snapshots.
regards, tom lane