Re: Fix parallel vacuum buffer usage reporting

On Mon, Apr 22, 2024 at 5:07 PM Anthonin Bonnefoy
<anthonin(dot)bonnefoy(at)datadoghq(dot)com> wrote:
>
> On Sat, Apr 20, 2024 at 2:00 PM Alena Rybakina <lena(dot)ribackina(at)yandex(dot)ru> wrote:
>>
>> Hi, thank you for your work with this subject.
>>
>> While I was reviewing your code, I noticed that your patch conflicts with another patch [0] that been committed.
>>
>> [0] https://www.postgresql.org/message-id/flat/CA%2BhUKGJkOiOCa%2Bmag4BF%2BzHo7qo%3Do9CFheB8%3Dg6uT5TUm2gkvA%40mail.gmail.com
>
>
> I've rebased the patch and also split the changes:

Thank you for updating the patch!

> 1: Use pgBufferUsage in Vacuum and Analyze block reporting

I think that if the anayze command doesn't have the same issue, we
don't need to change it. Making the vacuum and the analyze consistent
is a good point but I'd like to avoid doing unnecessary changes in
back branches. I think the patch set would contain:

(a) make lazy vacuum use BufferUsage instead of
VacuumPage{Hit,Miss,Dirty}. (backpatched down to pg13).
(b) make analyze use BufferUsage and remove VacuumPage{Hit,Miss,Dirty}
variables for consistency and simplicity (only for HEAD, if we agree).

BTW I realized that VACUUM VERBOSE running on a temp table always
shows the number of dirtied buffers being 0, which seems to be a bug.
The patch (a) will resolve it as well.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com