On 9/22/26 21:02, Nikolay Samokhvalov wrote: > On Tue, Sep 22, 2026 at 8:23 AM Tomas Vondra <[email protected]> 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. >
Yeah, that's a good point. The comment is misleading. I didn't consider that read_stream_next_buffer() is called from _reset() when I wrote it. Will think how to clarify it. regards -- Tomas Vondra
