Re: Improve eviction algorithm in ReorderBuffer

On Fri, Feb 9, 2024 at 7:35 PM Ajin Cherian <itsajin(at)gmail(dot)com> wrote:
>
>
>
> On Tue, Feb 6, 2024 at 5:06 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>>
>>
>> I've attached the new version patch set.
>>
>> Regards,
>>
>>
>> --
>> Masahiko Sawada
>> Amazon Web Services: https://aws.amazon.com
>
>
> Thanks for the patch. I reviewed that patch and did minimal testing and it seems to show the speed up as claimed. Some minor comments:

Thank you for the comments!

> patch 0001:
>
> +static void
> +bh_enlarge_node_array(binaryheap *heap)
> +{
> + if (heap->bh_size < heap->bh_space)
> + return;
>
> why not check "if (heap->bh_size >= heap->bh_space)" outside this function to avoid calling this function when not necessary? This check was there in code before the patch.

Agreed.

>
> patch 0003:
>
> +/*
> + * The threshold of the number of transactions in the max-heap (rb->txn_heap)
> + * to switch the state.
> + */
> +#define REORDE_BUFFER_MEM_TRACK_THRESHOLD 1024
>
> Typo: I think you meant REORDER_ and not REORDE_

Fixed.

These comments are addressed in the v4 patch set I just shared[1].

Regards,

[1] https://www.postgresql.org/message-id/CAD21AoDhuybyryVkmVkgPY8uVrjGLYchL8EY8-rBm1hbZJpwLw%40mail.gmail.com

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