RE: Force streaming every change in logical decoding

On Fri, Dec 23, 2022 1:50 PM Amit Kapila <amit.kapila16@gmail.com>
> 
> On Thu, Dec 22, 2022 at 6:18 PM shiy.fnst@fujitsu.com
> <shiy.fnst@fujitsu.com> wrote:
> >
> >
> > Besides, I tried to reduce data size in streaming subscription tap tests by this
> > new GUC (see 0002 patch). But I didn't covert all streaming tap tests
> because I
> > think we also need to cover the case that there are lots of changes. So, 015*
> is
> > not modified. And 017* is not modified because streaming transactions and
> > non-streaming transactions are tested alternately in this test.
> >
> 
> I think we can remove the newly added test from the patch and instead
> combine the 0001 and 0002 patches. I think we should leave the
> 022_twophase_cascade as it is because it can impact code coverage,
> especially the below part of the test:
> # 2PC PREPARE with a nested ROLLBACK TO SAVEPOINT
> $node_A->safe_psql(
>     'postgres', "
>     BEGIN;
>     INSERT INTO test_tab VALUES (9999, 'foobar');
>     SAVEPOINT sp_inner;
>     INSERT INTO test_tab SELECT i, md5(i::text) FROM
> generate_series(3, 5000) s(i);
> 
> Here, we will stream first time after the subtransaction, so can
> impact the below part of the code in ReorderBufferStreamTXN:
> if (txn->snapshot_now == NULL)
> {
> ...
> dlist_foreach(subxact_i, &txn->subtxns)
> {
> ReorderBufferTXN *subtxn;
> 
> subtxn = dlist_container(ReorderBufferTXN, node, subxact_i.cur);
> ReorderBufferTransferSnapToParent(txn, subtxn);
> }
> ...
> 

OK, I removed the modification in 022_twophase_cascade.pl and combine the two patches.

Please see the attached patch.
I also fixed Kuroda-san's comments[1].

[1] https://www.postgresql.org/message-id/TYAPR01MB5866CD99CF86EAC84119BC91F5E99%40TYAPR01MB5866.jpnprd01.prod.outlook.com

Regards,
Shi yu