-- 指标聚合表唯一约束：GORM 的 ON CONFLICT upsert 需要唯一索引才能真正生效。 // Logan.Li
DELETE FROM monitor_metric_aggregates
 WHERE id NOT IN (
   SELECT MAX(id) FROM monitor_metric_aggregates
   GROUP BY hostname, metric, "interval", bucket_time
 );

CREATE UNIQUE INDEX IF NOT EXISTS uniq_metric_agg ON monitor_metric_aggregates (hostname, metric, "interval", bucket_time);