Horton

RE: Conflict detection for update_deleted in logical replication

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

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From: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
To: shveta malik <shveta.malik@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>
Cc: 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>, vignesh C <vignesh21@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>
Date: 2025-09-15T07:36:56Z
Lists: pgsql-hackers

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On Monday, September 15, 2025 12:55 PM shveta malik <shveta.malik@gmail.com> wrote:
> 
> One concern:
> 
>   if (should_stop_conflict_info_retention(rdt_data))
> + {
> + /*
> + * Stop retention if not yet. Otherwise, reset to the initial phase to
> + * retry all phases. This is required to recalculate the current wait
> + * time and resume retention if the time falls within
> + * max_retention_duration.
> + */
> + if (MySubscription->retentionactive)
> + rdt_data->phase = RDT_STOP_CONFLICT_INFO_RETENTION;
> + else
> + reset_retention_data_fields(rdt_data);
> +
>   return;
> + }
> 
>  Instead of above code changes, shall we have:
> 
>  if (should_stop_conflict_info_retention(rdt_data))
>      rdt_data->phase = RDT_STOP_CONFLICT_INFO_RETENTION;
> (always)
> 
> And then stop_conflict_info_retention() should have these checks:
> 
> if (MySubscription->retentionactive)
> {
>     ...update flag and perform stop (current functionality)
> }
> else
> {
> 
> Assert(!TransactionIdIsValid(MyLogicalRepWorker->oldest_nonremovable_xi
> d));
>         reset_retention_data_fields(rdt_data);
> }

Thanks for the suggestion. I refactored the codes according to this.

Here is V65 patch which also addressed Amit's comments[1].

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.