Re: Panic during xlog building with big values

Maksim.Melnikov <m.melnikov@postgrespro.ru>

From: "Maksim.Melnikov" <m.melnikov@postgrespro.ru>

To: andrew.pogrebnoi@percona.com

Cc: pgsql-hackers@lists.postgresql.org

Date: 2025-10-14T07:08:12Z

Lists: pgsql-hackers

Commits

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

docs: Fix protocol version 3.2 message format of CancelRequest
- d3ba50db48e6 19 (unreleased) cited

Attachments

v3-0001-Pre-check-potential-XLogRecord-oversize.patch (text/x-patch) patch v3-0001

Hi, Andy, thanks for your review!

I've checked RecordTransactionCommit too, but I don't think it can fire 
similar error. Problem, that was described above, occurred because we 
used external column storage without compression and with REPLICA 
IDENTITY FULL.
To be honest, it's degenerate case, that can occur only in case of tuple 
update/delete, when we need full row to identify updated/deleted value, 
more info can be found in doc [1].

I've fixed comments with yours remarks, thanks. Patch is attached.

Also rebased patch with commit d3ba50db48e66be8804b9edf093b0f921d625425.

[1] 
https://www.postgresql.org/docs/current/logical-replication-publication.html

Best regards,
Maksim Melnikov