RE: Conflict detection for update_deleted in logical replication

Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>

From: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: shveta malik <shveta.malik@gmail.com>, vignesh C <vignesh21@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, Nisha Moond <nisha.moond412@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-06-23T10:50:09Z
Lists: pgsql-hackers

Attachments

On Mon, Jun 23, 2025 at 3:02 PM Amit Kapila wrote:
> 
> On Fri, Jun 20, 2025 at 4:48 PM Zhijie Hou (Fujitsu) 
> <houzj.fnst@fujitsu.com>
> wrote:
> >
> > Here is the V39 patch set which includes the following changes:
> >
> 
> 1.
> -static void
> -create_conflict_slot_if_not_exists(void)
> +void
> +ApplyLauncherCreateConflictDetectionSlot(void)
> 
> I am not so sure about adding ApplyLauncher in front of this function 
> name. I see most others exposed from this file add such a prefix, but 
> this one looks odd to me as it has nothing specific to the launcher, though we use it in launcher?
> How about CreateConflictDetectionSlot(void)?

Agreed and changed as suggested.

> 
> 2.
>  static void
>  create_logical_replication_slots(void)
>  {
> + if (!count_old_cluster_logical_slots())
> + return;
> +
> 
> Doing this count twice (once here and once at the caller of
> create_logical_replication_slots) seems redundant.

I have changed to check the slot numbers before entering the function and
declared a flag to save the results of Count_old_xxslots() function to avoid
counting it twice.

> 
> Apart from the above, attached please find a diff patch atop 0001, 
> 0002, 0003. I think the first three patches look in a reasonable shape 
> now, can we merge them (0001, 0002, 0003)?

Thanks for the diff, it looks good to me.

I have merged 0001~0003 and the diff.

Here is the V40 patch set which includes the following changes:

0001:
* Merged V39-0001 ~ 0003 into one patch.
* Addressed the comments above.
* Addressed Shveta's comments[1].

0002:
No change

0003:
No change

0004:
No change

0005:
No change

0006:
No change

[1] https://www.postgresql.org/message-id/CAJpy0uChWC4MLt_d8EwmKRrYKQYfVQKJrng4KVgktr5v25HP5w%40mail.gmail.com

Best Regards,
Hou zj

Commits

  1. Fix intermittent BF failures in 035_conflicts.

  2. Resume conflict-relevant data retention automatically.

  3. Fix intermittent test failure introduced in 6456c6e2c4.

  4. Fix Coverity issue reported in commit a850be2fe.

  5. Add test to prevent premature removal of conflict-relevant data.

  6. Post-commit review fixes for 228c370868.

  7. Add max_retention_duration option to subscriptions.

  8. Detect and report update_deleted conflicts.

  9. Preserve conflict-relevant data during logical replication.

  10. Integrate FullTransactionIds deeper into two-phase code

  11. Improve checks for GUC recovery_target_timeline

  12. Prevent excessive delays before launching new logrep workers.

  13. Keep WAL segments by slot's last saved restart LSN

  14. Rework some code handling pg_subscription data in psql and pg_dump

  15. Use generateClonedIndexStmt to propagate CREATE INDEX to partitions.