Re: Optimize SnapBuildPurgeOlderTxn: use in-place compaction instead of temporary array - Mailing list pgsql-hackers

Hi Neil,

On Thu, Jan 8, 2026 at 4:49 PM Neil Chen <carpenter.nail.cz@gmail.com> wrote:
>
> Hi Xuneng,
>
> On Thu, Jan 8, 2026 at 4:15 PM Xuneng Zhou <xunengzhou@gmail.com> wrote:
>>
>>
>> v3-0001 fixes a critical issue where the snapshot->xip array in
>> SnapBuildBuildSnapshot might not be sorted before reaching the
>> consistent state. Sorry for the noise here.
>>
>
> I’ve given this patch a cursory review, and it looks good overall.
> Considering the impact of this change, should we add a regression test for it, or provide a unit test to ensure the
correctnessof the modification? 
> I think it would be more receptive to merging such a "subtle performance optimization" only when its correctness is
fullyguaranteed. 

Thanks for your review. I think we can add a tap test for it.

--
Best,
Xuneng