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Re: BUG #18146: Rows reappearing in Tables after Auto-Vacuum Failure in PostgreSQL on Windows

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, Laurenz Albe <laurenz.albe@cybertec.at>, rootcause000@gmail.com, pgsql-bugs@lists.postgresql.org
Date: 2023-10-12T03:36:53Z
Lists: pgsql-bugs 
On Thu, Oct 12, 2023 at 5:59 AM Robert Haas <robertmhaas@gmail.com> wrote:
> Suppose that RelationTruncate set both DELAY_CHKPT_START and
> DELAY_CHKPT_COMPLETE. I think that would prevent this problem. P2
> could still choose the redo LSN after P1 logged the truncate, but it
> wouldn't then be able to reach CheckPointBuffers() until after P1 had
> reached RegisterSyncRequest. [...]

Thanks for thinking about this.  Yeah, the existing _START flag does
indeed seem to be enough.  I'd been focusing on trying to control the
redo point selection, but we just need to delay ProcessSyncRequests(),
and we had a hammer for that already.  Who wants to write the patch?
It should be trivial, except for the comments.

It's interesting that we'd stun the checkpointer just before we try to
send it a request in a fixed size queue, but that's OK because we'll
perform the fsync ourselves if the queue is full.

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix C error reported by Oracle compiler.

  2. Restore smgrtruncate() prototype in back-branches.

  3. Fix corruption when relation truncation fails.

  4. RelationTruncate() must set DELAY_CHKPT_START.

  5. WAL-log inplace update before revealing it to other sessions.

  6. Fix bugs in MultiXact truncation

  7. Fix possible recovery trouble if TRUNCATE overlaps a checkpoint.