Re: index prefetching

Hi,

On 2025-08-15 15:42:10 -0400, Peter Geoghegan wrote:
> On Fri, Aug 15, 2025 at 3:38 PM Andres Freund <andres@anarazel.de> wrote:
> > I see absolutely no effect of the patch with shared_buffers=1GB and a
> > read-only scale 200 pgbench at 40 clients. What data sizes, shared buffers
> > etc. were you testing?
> 
> Just to be clear: you are testing with both the index prefetching
> patch and your patch together, right? Not just your own patch?

Correct.


> My shared_buffers is 16GB, with pgbench scale 300.

So there's actually no IO, given that a scale 300 is something like 4.7GB? In
that case my patch could really not make a difference, neither of the changed
branches would ever be reached?

Or were you testing the warmup phase, rather than the steady state?

Greetings,

Andres Freund