Horton

Re: Conflict detection for update_deleted in logical replication

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: shveta malik <shveta.malik@gmail.com>
Cc: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.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: 2025-05-20T04:54:14Z
Lists: pgsql-hackers 
On Tue, May 20, 2025 at 8:38 AM shveta malik <shveta.malik@gmail.com> wrote:
>
> Please find few more comments:
>
> 1)
> ProcessStandbyPSRequestMessage:
> + /*
> + * This shouldn't happen because we don't support getting primary status
> + * message from standby.
> + */
> + if (RecoveryInProgress())
> + elog(ERROR, "the primary status is unavailable during recovery");
>
>
> a) This error is not clear. Is it supposed to be user oriented error
> or internal error? As a user, it is difficult to interpret this error
> and take some action.
>

This is an internal error for developers to understand that they have
sent the wrong message. Do you have any suggestions to change it?

> b) What I understood is that there is no user of enabling
> 'retain_conflict_info' for a subscription which is subscribing to a
> publisher which is physical standby too. So shall we emit such an
> ERROR during 'Create Sub(retain_conflict_info=on)' itself? But that
> would need checking whether the publisher is physical standby or not
> during CREATE-SUB. Is that a possibility?
>

The 0003 patch already took care of this, see check_conflict_info_retaintion.

-- 
With Regards,
Amit Kapila.

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.