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: 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: 2025-06-30T13:28:35Z
Lists: pgsql-hackers

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On Mon, Jun 30, 2025 at 7:22 PM Amit Kapila wrote:
> 
> On Fri, Jun 27, 2025 at 7:58 AM Zhijie Hou (Fujitsu) <houzj.fnst@fujitsu.com>
> wrote:
> >
> > Here is the V43 patch set which includes the following changes:
> >
> 
> Few minor comments:
> 1.
> @@ -29645,8 +29651,10 @@ postgres=# SELECT '0/0'::pg_lsn +
> pd.segment_number * ps.setting::int + :offset
>          Copies an existing logical replication slot
>          named <parameter>src_slot_name</parameter> to a logical
> replication
>          slot named <parameter>dst_slot_name</parameter>, optionally
> changing
> -        the output plugin and persistence.  The copied logical slot starts
> -        from the same <acronym>LSN</acronym> as the source logical slot.
> Both
> +        the output plugin and persistence.  The name cannot be
> +        <literal>pg_conflict_detection</literal> as it is reserved for
> +        the conflict detection.  The copied logical slot starts from the same
> +        <acronym>LSN</acronym> as the source logical slot.  Both
> 
> /The name/The new slot name
> 
> 2. The server version checks can be modified to 19000 as a new branch is
> created now.
> 
> 3.
> This ensures that if the launcher loses track of the slot after
> +   * a restart, it will remember to drop the slot when it is no longer
> +   * requested by any subscription.
> 
> The link between the first part of the sentence before the comma is not clear
> with the remaining part of the sentence. How about writing it as: "Acquire the
> conflict detection slot at startup to ensure it can be dropped if no longer needed
> after a restart."?

Thanks for the comments. I have addressed above in V44 patch set.

Only 0001 is modified in this version.

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.