PostgreSQL TOAST and QEMU 9pfs, Realms updates

PostgreSQL hackers advanced storage, replication, and statistics patches while QEMU developers addressed a 9pfs security race and Arm confidential computing support. Partition detach stability and aarch64 host model work rounded out the day.

8-byte TOAST pointer support advances

PostgreSQL hackers continued review of a patch adding support for 8-byte TOAST values. Compatibility impact on extensions received explicit note during discussion. Extension authors and operators of large-object workloads should track the change for interface effects.

QEMU 9pfs FID path race fixed

A patch on the QEMU list resolves CVE-2026-93834 by confining FID path mutation to the main thread in the 9pfs code. The change eliminates a race previously possible from worker threads. Users of 9p filesystem passthrough in QEMU need the fix once integrated.

Crashes after interrupted concurrent detach

Developers reported crashes on partitions whose DETACH PARTITION CONCURRENTLY never finished and supplied patches. The thread also covers a PostgreSQL 19 regression in publication handling. Sites that rely on concurrent partition operations require the corrections to restore stability.

Slot invalidation persistence ordering

A patch ensures replication slot invalidations are written to disk before they are published in shared memory. The ordering change prevents restart inconsistencies that arise when in-memory state outruns persistence. Replication deployments gain more reliable slot behavior across crashes and restarts.

Arm Realm support RFC for QEMU

An RFC v4 series of 24 patches adds Arm RME Realm confidential VM support to QEMU-VMM. The work is designed to stay compatible with recent KVM CCA changes. Confidential computing stacks on Arm gain a concrete path into the QEMU VMM.

PRODUCT() aggregate under review

Hackers examined a patch that introduces a PRODUCT() aggregate, focusing on performance, overflow behavior, and SQL-standard ON EMPTY syntax. The function would let SQL express multiplicative aggregation directly. Query authors interested in standard aggregate extensions have reason to follow the review.

Customizable aarch64 KVM host model

Version 9 of a 26-patch series adds writable ID register fields to the aarch64 KVM host model in QEMU. The goal is finer control over guest migration. Arm virtualization maintainers who manage cross-host guest movement should watch the series.

Backend stats permission checks added

A patch inserts missing HAS_PGSTAT_PERMISSIONS checks into four backend statistics functions, including pg_stat_get_backend_subxact(). Discussion also identified a snapshot consistency issue tied to PID reuse. Installations that expose backend statistics tighten access control with the change.