PostgreSQL replication fixes and QEMU CPR, security updates

PostgreSQL hackers advanced patches for logical decoding, conflict logging, UNDO recovery, backup verification, and relcache memory use. QEMU saw a CPR mode proposal for kexec host updates, a merged security pull, and a QOM refactor for multi-target builds.

Logical decoding bug with DDL and subtransactions

Patch v5 for logical decoding bug 19555, an assert failure involving DDL and subtransactions on tuplecid, is under review for backport to all stable branches. Discussion on pgsql-hackers involves seven participants iterating on the fix. Logical decoding underpins replication, so a correct backport matters for release stability.

Conflict log history table for logical replication

PostgreSQL hackers are reviewing and iterating on patches that add a conflict log history table for logical replication. The thread draws fourteen participants across extensive design discussion. Operators gain durable visibility into replication conflicts once the feature lands.

QEMU cpr-luo mode for kexec host kernel updates

A twenty-one patch series proposes a cpr-luo checkpoint and restore mode that uses LUO and KHO so the host can kexec a new kernel while preserving guest RAM. Two participants are working the series on qemu-devel. The change would let operators update the host kernel without tearing down running guests.

UNDO with constant-time recovery for FILEOPS

Greg Burd posted a v2 patch series that adds UNDO for FILEOPS with claimed constant-time rollback. Four participants on pgsql-hackers have begun design and bug feedback. Faster rollback would improve recovery behavior for file-oriented operations.

Detection of truncated compressed backups

A patchset corrects pg_verifybackup so it detects truncated zstd, gzip, and lz4 backups. Five participants are reviewing the changes and associated tests on pgsql-hackers. Reliable verification of compressed backups is required for trustworthy restore workflows.

Relcache memory reduction via index shape deduplication

A patchset deduplicates index shape data inside the relcache and introduces a proxy memory context to shrink RelationData. Six participants are discussing the approach on pgsql-hackers. Lower relcache footprint benefits instances that keep many relations open.

QEMU misc fixes including websocket CVE

A maintainer merged a four-patch pull that includes CVE-2026-101291, an unbounded read in the websocket code, plus a use-after-free fix. Three participants handled the series on qemu-devel. The security fixes close concrete issues in virtualization hosts.

QOM TargetInfo for multi-target binaries

An eight-patch series passes TargetInfo into the QOM is_available callback to support multi-target combined binaries. Four participants refined the design across dozens of messages on qemu-devel. The refactor cleans the path for single binaries that cover multiple architectures.