Re: Vacuum ERRORs out considering freezing dead tuples from before OldestXmin

On Wed, Jun 18, 2025 at 8:05 AM Melanie Plageman
<melanieplageman@gmail.com> wrote:

> What's odd is that I'm seeing now that I need at least 8000 tuples to
> get > 1 pass of index vacuuming locally with a 64-bit assert build --
> which is more than you are reporting and more than I remember having
> needed for 64-bit builds when I tested this last year with your patch
> applied.
>
> What's even odder is that I tested on a 32-bit build as well (
> -Dc_args='-m32' -Dc_link_args='-m32' --auto-features=disabled) and it
> doesn't require any more than 8000 tuples to get > 1 pass of index
> vacuuming.
>
> So, currently, on both 32 and 64 bit builds and nrows == 8000, I get 2
> passes of index vacuuming.
>
> I can't tell what I'm doing wrong. Could you give your full build
> details?

Here's what numbers I'm looking at as well:

*** normal
meson options: -Dcassert=true -Ddebug=true -Dc_args='-Og'
-Dc_args='-fno-omit-frame-pointer'

$ meson test -q --print-errorlogs --suite setup && meson test -q
--print-errorlogs recovery/048_vacuum_horizon_floor

$ grep finished
build-debug/testrun/recovery/048_vacuum_horizon_floor/log/048_vacuum_horizon_floor_primary.log

2025-06-18 10:08:19.072 +07 [5730] 048_vacuum_horizon_floor.pl INFO:
finished vacuuming "test_db.public.vac_horizon_floor_table": index
scans: 12

*** 32-bit
meson options: -Dcassert=true -Ddebug=true --auto-features=disabled
-Dtap_tests=enabled -Dc_args='-m32' -Dc_link_args='-m32'

$ meson test -q --print-errorlogs --suite setup && meson test -q
--print-errorlogs recovery/048_vacuum_horizon_floor

$ grep finished
build-debug32/testrun/recovery/048_vacuum_horizon_floor/log/048_vacuum_horizon_floor_primary.log

2025-06-18 10:27:43.088 +07 [22796] 048_vacuum_horizon_floor.pl INFO:
finished vacuuming "test_db.public.vac_horizon_floor_table": index
scans: 5

> There's no chance that you made a change to the TIDStore that
> would make it possible for any configuration to have the same size
> TIDStore on a 32 and 64 bit build, right?

Not yet.

--
John Naylor
Amazon Web Services