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# 系统。asynchronous_metrics {#system_tables-asynchronous_metrics}
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包含在后台定期计算的指标。 例如，
列:
- `metric` ([字符串](../../sql-reference/data-types/string.md)) — Metric name.
- `value` ([Float64](../../sql-reference/data-types/float.md)) — Metric value.
**示例**
``` sql
SELECT * FROM system.asynchronous_metrics LIMIT 10
```
``` text
┌─metric──────────────────────────────────┬──────value─┐
│ jemalloc.background_thread.run_interval │ 0 │
│ jemalloc.background_thread.num_runs │ 0 │
│ jemalloc.background_thread.num_threads │ 0 │
│ jemalloc.retained │ 422551552 │
│ jemalloc.mapped │ 1682989056 │
│ jemalloc.resident │ 1656446976 │
│ jemalloc.metadata_thp │ 0 │
│ jemalloc.metadata │ 10226856 │
│ UncompressedCacheCells │ 0 │
│ MarkCacheFiles │ 0 │
└─────────────────────────────────────────┴────────────┘
```
**另请参阅**
- [监测 ](../../operations/monitoring.md ) — Base concepts of ClickHouse monitoring.
- [系统。指标 ](../../operations/system-tables/metrics.md#system_tables-metrics ) — Contains instantly calculated metrics.
- [系统。活动 ](../../operations/system-tables/events.md#system_tables-events ) — Contains a number of events that have occurred.
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- [系统。metric_log ](../../operations/system-tables/metric_log.md#system_tables-metric_log ) — Contains a history of metrics values from tables `system.metrics` и `system.events` .
