지역별 데이터베이스 복제본 부실 상태 측정

SELECT
  region,
  replica_role,
  operation_name,
  COUNT(*) AS reads,
  approx_percentile_cont(replay_lag_ms, 0.95) AS p95_replay_lag_ms,
  SUM(CASE WHEN consistency_outcome = 'stale' THEN 1 ELSE 0 END)
    AS stale_reads,
  SUM(CASE WHEN consistency_outcome = 'failed' THEN 1 ELSE 0 END)
    AS failed_reads
FROM database_replica_read_events
WHERE timestamp_utc >= now() - INTERVAL '24 hours'
GROUP BY region, replica_role, operation_name
ORDER BY stale_reads DESC, p95_replay_lag_ms DESC;