PostgreSQL integrity fixes and QEMU APX work

PostgreSQL developers chased several correctness bugs in heap tuples, partitions, replication slots, and type alteration, while QEMU advanced x86 TCG with APX support and a revised AI contribution policy.

PostgreSQL patch fixes ctid corruption after GiST KNN scans

A patch on pgsql-hackers corrects missing tts_tid handling in ExecForceStoreHeapTuple. The defect could cause ctid corruption, unintended table extension, and invalid pages when FOR UPDATE followed GiST KNN scans. Operators using GiST indexes with concurrent updates face a real integrity risk until the fix lands.

QEMU proposes new policy for AI-generated contributions

An RFC patch series on qemu-devel outlines a completely new policy requiring metadata alongside DCO sign-off for AI-generated contributions. Seven participants debated the legal implications of the approach. The outcome will shape how outside code is accepted into the project.

QEMU TCG gains Intel APX instruction support

Paolo Bonzini posted a 17-patch series implementing Advanced Performance Extensions in the QEMU x86 TCG decoder. The work adds EVEX prefix handling and new instructions including CCMP, CFCMOV, and PUSH2. Emulator users targeting upcoming Intel CPUs obtain earlier functional coverage.

PostgreSQL 18 partition attach slows with large pg_constraint

ATTACH PARTITION cost now grows linearly with pg_constraint size because of a sequential scan in CloneFkReferenced, made worse after not-null constraints moved into that catalog in PostgreSQL 18. A patch proposes an index on confrelid to cut the overhead. Sites with many partitions or constraints will see longer attach times until the index is adopted.

ROLLBACK of SET TABLESPACE can leave index and heap inconsistent

BUG #19686 discussion examines index and heap inconsistency after ROLLBACK of ALTER TABLE SET TABLESPACE. Participants are refining a patch so the two structures stay aligned on the abort path. Reliable tablespace changes under transaction control matter for recovery and migration workflows.

Replication slot invalidations must persist before publish

A patch ensures slot invalidations are written to disk before their shared-memory state is published. Without that ordering, a restart can leave inconsistent slot state. Replication deployments gain fewer surprises after crashes or restarts.

ALTER TYPE on domain-referenced composites can raise internal error

A v1 patch addresses Bug #19724, where ALTER TYPE ... ALTER ATTRIBUTE triggered an internal error in ATPostAlterTypeCleanup when a composite type was referenced by a domain check constraint. Schema changes involving domains and composites become more reliable once the cleanup path is fixed.

QEMU pull request bundles APX and x86 TCG fixes

Paolo Bonzini sent a 30-patch pull request that includes the APX work plus assorted target/i386 and miscellaneous changes for 2026-09-28. The series consolidates recent TCG improvements for the next merge window.