Re: Restructured Shared Buffer Hash Table

On Tue, Oct 13, 2026 at 5:38 AM Dhruv Aron <dhruv(dot)aron(at)gmail(dot)com> wrote:

> On Mon, Oct 12, 2026 at 3:08 PM Alexandre Felipe <
> o(dot)alexandre(dot)felipe(at)gmail(dot)com> wrote:
>
>> 1.5 * num_bucket implicitly casts to floating point, and later back to
>> integer, that was not meant to be permanent.
>> A safer option would be (num_buckets | (num_buckets >> 1)), no
>> wrap-around if some day
>> this gets increased to UINT_MAX. Or simply num_buckets, without
>> multiplication at all.
>>
>
> Apologies, I am experiencing trouble finding the line where we perform
> "1.5 * num_bucket"; perhaps it has been too long since I last worked on the
> patch.
> Could you point me towards where it is in the
> restructured_shared_buffer_table.patch file?
> Otherwise, yes, the bitwise arithmetic in this case should also be more
> performant.
>

It was a modification that I did
https://www.postgresql.org/message-id/CAE8JnxPMMfdnWWQO18gHwEmkmdCu9KwuqbWRb6DkfKQ-H%2Bm_PA%40mail.gmail.com

If you are working from your original patch my comment doesn't apply.

Regards,
Alexandre