{"id":"wal-no-concurrent-group-commit","text":"The WAL uses a single `threading.Lock` and a write counter for batch sync rather than a concurrent waiter queue, so it cannot amortize fsync cost across concurrent callers the way PostgreSQL's group commit does.","truth_value":"IN","source":"entries/2026/05/29/topic-group-commit-optimization.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"explanation":{"steps":[{"node":"wal-no-concurrent-group-commit","truth_value":"IN","reason":"premise"}]}}