Re: Buffer usage detailed by RelKind in EXPLAIN ANALYZE BUFFERS

Hi,

On 2023-02-13 16:36:25 -0800, Andrey Borodin wrote:
> On Mon, Feb 13, 2023 at 4:29 PM Andres Freund <andres@anarazel.de> wrote:
> > > 1. Some more increments on hot paths. We have to add this tiny toll to
> > > every single buffer hit, but it will be seldom of any use.
> >
> > Additionally, I bet it slows down EXPLAIN (ANALYZE, BUFFERS) noticeably. It's
> > already quite expensive...
> >
> 
> I think collection of instrumentation is done unconditionally.
> We always do that
> pgBufferUsage.shared_blks_hit++;
> when the buffer is in shared_buffers.

The problem I'm talking about is the increased overhead in InstrStopNode(),
due to BufferUsageAccumDiff() getting more expensive.

Andres