Re: [PATCH] Add memory usage reporting to VACUUM VERBOSE

On Sun, Dec 21, 2025 at 9:09 AM Tatsuya Kawata
<kawatatatsuya0913(at)gmail(dot)com> wrote:
>
> Hi Sawada-san,
>
> Thank you for your review on the v7 patch!
> I have updated the patch based on your feedback.
>
> > IIUC this line aims to add the initial data related to TidStore including underlying radix tree and the bump context to the total memory usage. I'm not sure why we do that only when no dead items are collected. If we add these sizes, should we do that also when the TidStore is reset due to being full and there are no dead items in the subsequent blocks, no? I guess it would make more sense to consider adding TidStoreMemoryUsage() also before cleaning up the TidStore.
> You're right and my previous patch is not correct.
> I adopted Chao's suggestion from the previous thread.
>
> > I think it's not correct that we say "memory allocated: 64.00MB" in this case because we don't actually allocate 64MB. Since we're using a TidStore for dead items storage, we incrementally allocate its space when needed.
> I agree. I reverted to your earlier suggested wording "limit was %.2f MB" which more accurately describes that this is the configured memory limit, not the actual allocated amount. The updated message format is:
> memory usage: 0.02 MB in total, with dead-item storage reset 0 times (limit was 64.00 MB)
>

Thank you for updating the patch!

The patch mostly looks good to me. I've made some cosmetic changes to
the comments (as well as the commit message) and attached the updated
patch. Please review it.

Regards,

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