On 26/02/2026 16:26, Maxim Orlov wrote:
Beginning of the discussion is here [0].
Historically, the SLRU module was designed to handle 32-bit
transactions. However, it is now utilised for handling a variety of
object types, like TransactionId, MultixactId, MultiXactOffset,
QueuePosition, and so on. But the IO error reporting system is still
designed to support 32-bit XIDs exclusively.
The proposed patchset allows us to define a "custom" callback to
improve error messages.
The first two commits add a callback and test case. The subsequent ones
improve I/O error messages. The last one adds the XID epoch to the error
message. It's purely optional, but I think it would be useful.
[0] https://www.postgresql.org/message-id/
CACG%3Dezbwy1zargXDNPeYXxZwRW3jXu_aD%3DrcG-7dc4fw7Y9Ojw%40mail.gmail.com
<https://www.postgresql.org/message-id/
CACG%3Dezbwy1zargXDNPeYXxZwRW3jXu_aD%3DrcG-7dc4fw7Y9Ojw%40mail.gmail.com>
Thanks, looks reasonable.
I'm -1 on the last patch, "Expand xact SLRU IO-error to show epoch"
though. The epoch isn't used in addressing the SLRU, the patch just
expands the 32-bit XID into a full 64-bit XID using the current epoch.
That seems misleading.
- Heikki
