PostgreSQL: Closing the Gaps on Concurrent Race Conditions
Today's commits center on a cluster of subtle race conditions and edge-case bugs involving concurrent operations - from stale LSN wakeups to REINDEX CONCURRENTLY interactions with foreign keys - alongside cleanup work on overflow safety and reloption handling.
Duration: PT2M44S
Episode overview
This episode is a short developer briefing from PostgreSQL.
It explains recent repository work in plain language.
- Show: PostgreSQL
- Published: 2026-08-18T13:03:37Z
- Audio duration: PT2M44S
Transcript excerpt
This excerpt keeps the crawler page concise. Listen to the episode or use the RSS feed for the full update.
Good morning, it's August 18th, 2026, and this is your PostgreSQL briefing.
The dominant theme today is concurrency edge cases that only surface under real-world timing pressure. Three separate fixes target processes that get caught in the gap between checking a condition and acting on it.
Alexander Korotkov's commit 70b7e96 fixes LSN waiters that could go to sleep permanently if a wakeup went stale during WAL streaming restarts - the fix re-registers the waiter and rechecks position after re-adding, closing a window where progress could be silently missed. A follow-up, f994d2b, plugs a related gap:…
Amit Langote landed two related foreign key fixes. Commit d02a908 addresses a race where REINDEX CONCURRENTLY could repoint or drop an index between a foreign key check reading it and locking the referenced table - the fix reloads the constraint after locking to guarantee a consistent view. Commit cc449a5 fixes a…
A second theme is defensive overflow and safety hardening. Michael Paquier's hstore rework, commit 92e20d4, replaces integer size counters with proper overflow-checked size arithmetic to prevent wraparound during large key-value construction. Tom Lane's plperl fix, 131444c,…
Sepa…
Nearby episodes from PostgreSQL
- Subtransaction Edge Cases and Long-Overdue Cleanup
- Trusting Input, Fixing Silent Failures
- A Deep Dive Into Data Corruption Fixes
- Query Planner Gets Smarter About Nulls
- Small Fixes, Steady Hardening
- Weekly Recap - Cleanup, Correctness, and Closing Old Doors
- Housekeeping and Code Clarity
- Cleanup, Correctness, and Retiring Old Interfaces