Subject: pgsql: Don't reset 'latest_page_number' when replaying multixid truncat

From: Heikki Linnakangas <[email-masked]>
Date: Mon, 16 Feb 2026 16:01:49 +0000

Don't reset 'latest_page_number' when replaying multixid truncation

'latest_page_number' is set to the correct value, according to
nextOffset, early at system startup. Contrary to the comment, it hence
should be set up correctly by the time we get to WAL replay.

This fixes a failure to replay WAL generated on older minor versions,
before commit 789d65364c (18.2, 17.8, 16.12, 15.16, 14.21). The
failure occurs after a truncation record has been replayed and looks
like this:

    FATAL:  could not access status of transaction 858112
    DETAIL:  Could not read from file "pg_multixact/offsets/000D" at offset 24576: read too few bytes.
    CONTEXT:  WAL redo at 3/2A3AB408 for MultiXact/CREATE_ID: 858111 offset 6695072 nmembers 5: 1048228 (sh) 1048271 (keysh) 1048316 (sh) 1048344 (keysh) 1048370 (sh)

Reported-by: Sebastian Webber <[email-masked]>
Reviewed-by: Andrey Borodin <[email-masked]>
Reviewed-by: Kirill Reshke <[email-masked]>
Discussion: https://www.postgresql.org/message-id/[email-masked];lightning.p46.dedyn.io
Backpatch-through: 14-18

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/899de38d8f3b519e7fd5b2acf580d1c9282ee6f1

Modified Files
--------------
src/backend/access/transam/multixact.c | 9 ---------
src/include/access/slru.h              | 4 +++-
2 files changed, 3 insertions(+), 10 deletions(-)