On Tue, Sep 22, 2026 at 8:23 AM Tomas Vondra <tomas@vondra.me> wrote:
> It's not clear to me why this would be desirable. The query execution
> clearly *does* perform the I/O, even if the buffers end up not being
> used. Hiding that would be very confusing / misleading.
>
> In other words, I/O and buffers may disagree - that's not a bug. Those
> counters are tracking different things.
Thanks all. Agreed that issued I/O should remain accounted for.
Is Prefetch avg/max also intended to include buffers discarded by
read_stream_reset()? If so, agreed, the patch is wrong. The comment above
read_stream_count_prefetch() says it is called once per buffer returned
to the consumer.
Nik
