Re: Parallel heap vacuum

On Sun, Apr 6, 2025 at 1:02 AM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
>
> The eager freeze scan is the pre-existing feature but it's pretty new
> code that was pushed just a couple months ago. I didn't want to make
> the newly introduced code complex further in one major release
> especially if it's in a vacuum area. While I agree that disabling
> eager freeze scans during parallel heap vacuum is not very
> user-friendly, there are still many cases where parallel heap vacuum
> helps even without the eager freeze scan. FYI the parallel heap scan
> can be disabled by setting min_parallel_table_scan_size. So I thought
> we can incrementally improve this part.

min_parallel_table_scan_size also affects parallel sequential scans,
though. And AFAIK, that can only be configured globally (i.e. not for
a specific table).
I wonder if there is a clear way to make specific phases of vacuum
using parallelism configurable.

- Melanie