Horton

Re: Conflict detection for update_deleted in logical replication

Michail Nikolaev <michail.nikolaev@gmail.com>

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From: Michail Nikolaev <michail.nikolaev@gmail.com>
To: Nisha Moond <nisha.moond412@gmail.com>
Cc: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Amit Kapila <amit.kapila16@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Masahiko Sawada <sawada.mshk@gmail.com>, shveta malik <shveta.malik@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2024-10-25T10:20:48Z
Lists: pgsql-hackers 
Hello, Hayato!

> Thanks for updating the patch! While reviewing yours, I found a corner
case that
> a recently deleted tuple cannot be detected when index scan is chosen.
> This can happen when indices are re-built during the replication.
> Unfortunately, I don't have any solutions for it.

I just randomly saw your message, so, I could be wrong and out of the
context - so, sorry in advance.

But as far as I know, to solve this problem, we need to wait for slot.xmin
during the [0] (WaitForOlderSnapshots) while creating index concurrently.

[1]:
https://github.com/postgres/postgres/blob/68dfecbef210dc000271553cfcb2342989d4ca0f/src/backend/commands/indexcmds.c#L1758-L1765

Best regards,
Mikhail.

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.