Re: Maximize page freezing - Mailing list pgsql-hackers

From Matthias van de Meent
Subject Re: Maximize page freezing
Date
Msg-id CAEze2WhD5zhs5RamxUSj+KTuZ2twv7h93d=gMkHNhYRLNTJXLg@mail.gmail.com
Whole thread Raw
In response to Re: Maximize page freezing  (Simon Riggs <simon.riggs@enterprisedb.com>)
List pgsql-hackers
On Fri, 29 Jul 2022 at 16:38, Simon Riggs <simon.riggs@enterprisedb.com> wrote:
>
> On Thu, 28 Jul 2022 at 14:55, Matthias van de Meent
> <boekewurm+postgres@gmail.com> wrote:
> > Great idea, yet this patch seems to only freeze those tuples that are
> > located after the first to-be-frozen tuple. It should probably
> > re-visit earlier live tuples to potentially freeze those as well.
>
> Like this?

That wasn't quite what I imagined. In your patch, heap_page_prune is
disabled after the first frozen tuple, which makes the retry mechanism
with the HTSV check loop forever because it expects that tuple to be
vacuumed.

I was thinking more in the line of "do a backtrack in a specialized
code block when entering max_freeze_page mode" (without using
'retry'), though I'm not sure whether that's the best option
available.

Kind regards,

Matthias van de Meent



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