Re: Lowering the ever-growing heap->pd_lower

On Mon, 3 May 2021 at 16:26, John Naylor <john(dot)naylor(at)enterprisedb(dot)com> wrote:
>
> On Sat, Apr 3, 2021 at 10:07 PM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> > I would like to deal with this work within the scope of the project
> > we're discussing over on the "New IndexAM API controlling index vacuum
> > strategies" thread. The latest revision of that patch series includes
> > a modified version of your patch:
> >
> > https://postgr.es/m/CAH2-Wzn6a64PJM1Ggzm=uvx2otsopJMhFQj_g1rAj4GWr3ZSzw@mail.gmail.com
> >
> > Please take discussion around this project over to that other thread.
> > There are a variety of issues that can only really be discussed in
> > that context.
>
> Since that work has been committed as of 3c3b8a4b2689, I've marked this CF entry as committed.

I disagree that this work has been fully committed. A derivative was
committed that would solve part of the problem, but it doesn't cover
all problem cases. I believe that I voiced such concern in the other
thread as well. As such, I am planning on fixing this patch sometime
before the next commit fest so that we can truncate the LP array
during hot pruning as well, instead of only doing so in the 2nd VACUUM
pass. This is especially relevant on pages where hot is highly
effective, but vacuum can't keep up and many unused (former HOT) line
pointers now exist on the page.

With regards,

Matthias van de Meent