QEMU AI policy and PostgreSQL correctness work

QEMU advanced a revised AI contribution policy while PostgreSQL developers chased correctness bugs, replication durability, and memory savings. Several technical patch series moved through both projects.

QEMU revises AI contribution policy

QEMU posted version 4 of a documentation series that replaces a blanket ban on AI-generated contributions. The new policy introduces attestation trailers and requires pre-approval for large contributions. Contributors need to track the attestation rules and approval path before submitting AI-assisted work.

Eager aggregation wrong results for bpchar in PG19

A bug report and patch on pgsql-hackers show that eager aggregation in PostgreSQL 19 returns incorrect results for bpchar because of equalimage handling inside bpchar_ops. The defect affects aggregation correctness on character data. Developers testing PG19 builds should watch for the accompanying fix.

Replication slot invalidations persisted before publish

A patch on pgsql-hackers changes replication slot invalidation ordering so shared-memory state is not published until it has been written to disk. The ordering prevents restart inconsistencies after an invalidation. Operators running logical or physical replication gain stronger durability guarantees for slot state.

RISC-V vector load/store reorg in QEMU

The RISC-V maintainer posted version 2 of a 23-patch series that refactors vector load and store probes. The work reduces overhead and corrects alignment and page handling. Emulator and RISC-V developers obtain cleaner, more accurate vector memory access paths.

Relcache memory cut by index shape dedup

A patchset proposes deduplicating index shape data inside the relcache and adding a proxy memory context to shrink RelationData. The change targets lower memory use on systems with many relations and indexes. Deployments under relcache pressure may see reduced footprint once the series lands.

IMPLIES boolean operator for PostgreSQL

A patch adds an IMPLIES boolean operator that is right-associative and expands to NOT a OR b. Thread discussion covered associativity, NULL behavior, and operator precedence. SQL authors gain a direct way to express logical implication if the operator is accepted.

pg_upgrade skips invalid databases

A thread proposes that pg_upgrade skip, rather than fail on, invalid databases left by an interrupted DROP DATABASE. The change would smooth major-version upgrades of clusters that contain such remnants. Administrators running pg_upgrade on partially cleaned catalogs should note the proposed behavior.

Parallel autovacuum cost delay timing GUC

A small patch propagates track_cost_delay_timing to parallel autovacuum workers. It received positive review, minor revisions, and a suggestion to backpatch to version 19. Operators who rely on delay timing statistics obtain accurate figures from the worker processes.