PostgreSQL: Two Backpatched Fixes for v18
Two bug fixes landed for PostgreSQL 18, both backpatched, addressing a hot standby correctness issue that could return wrong query results and a vacuum failsafe inefficiency. Both trace back to regressions introduced by earlier commits in the same release.
Duration: PT2M15S
Episode overview
This episode is a short developer briefing from PostgreSQL.
It explains recent repository work in plain language.
- Show: PostgreSQL
- Published: 2026-08-08T13:03:20Z
- Audio duration: PT2M15S
Transcript excerpt
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Good morning. It's August 8th, and today's PostgreSQL activity is small but important: two backpatched fixes, both correcting regressions introduced earlier in version 18.
The headline fix comes from Fujii Masao, commit b597835. This addresses a hot standby bug where a replica could start accepting read-only connections before it actually reached data consistency. The root cause: when the postmaster re-forks the startup process after a crash reset, that new process inherits a stale…
The second fix, from Melanie Plageman, commit 6980055, is a performance correctness cleanup in vacuum's failsafe mode. When failsafe engages, vacuum is supposed to abandon its buffer access strategy once. Instead, a prior fix caused it to repeat that clearing operation on every single block scanned after failsafe…
The connecting thread here: both bugs are second-order regressions from earlier changes this release cycle, one in recovery consistency tracking, one in vacuum's read stream refactor. That's a useful reminder that state inherited across process forks, or state touched inside hot loops, deserves extra scrutiny during…
What's next: expect both fixes in upcoming minor releases for version 18. If…
Tha…
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