Re: Logical replication 'invalid memory alloc request size 1585837200' after upgrading to 17.5

Dear Hayato Kuroda, I tried
v4-PG17-0001-Avoid-distributing-invalidation-messages-sev.patch and I can
confirm that it also resolves my original issue.

Best wishes, Duncan.

On 28/05/2025 14:27, Hayato Kuroda (Fujitsu) wrote:
> Dear Sawada-san, Amit,
>
>>> It can impact the performance for large transactions with fewer
>>> invalidations, especially the ones which has spilled changes because
>>> it needs to traverse the entire list of changes again at the end.
>>
>> Agreed.
>>
>>> The
>>> other idea would be to add new member(s) in ReorderBufferTXN to
>>> receive distributed invalidations. For adding the new member in
>>> ReorderBufferTXN: (a) in HEAD, it should be okay, (b) for
>>> backbranches, we may be able to add at the end, but we should check if
>>> there are any extensions using sizeof(ReorderBufferTxn) and if they
>>> are using what we need to do.
>>
>> If we can make sure that that change won't break the existing
>> extensions, I think this would be the most reasonable solution.
>
> Based on the discussion, I created PoC for master/PG17. Please see attached.
> The basic idea is to introduce the new queue which only contains distributed inval
> messages. Contents are consumed at end of transactions. I feel some of codes can
> be re-used so that internal functions are introduced. At least, it could pass
> regression tests and workloads discussed here.
>
> Best regards,
> Hayato Kuroda
> FUJITSU LIMITED
>