ClickHouse/docs/en/operations/system-tables/asynchronous_metric_log.md
Rory Crispin c9a26d43c5 (docs) Remove async_metric_log event_time_microseconds
event_time_microseconds was removed from the
system.asynchronous_metric_log in
https://github.com/ClickHouse/ClickHouse/pull/36360
2023-07-04 12:06:15 +01:00

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---
slug: /en/operations/system-tables/asynchronous_metric_log
---
# asynchronous_metric_log
Contains the historical values for `system.asynchronous_metrics`, which are saved once per minute. Enabled by default.
Columns:
- `event_date` ([Date](../../sql-reference/data-types/date.md)) — Event date.
- `event_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — Event time.
- `name` ([String](../../sql-reference/data-types/string.md)) — Metric name.
- `value` ([Float64](../../sql-reference/data-types/float.md)) — Metric value.
**Example**
``` sql
SELECT * FROM system.asynchronous_metric_log LIMIT 10
```
``` text
┌─event_date─┬──────────event_time─┬─name─────────────────────────────────────┬─────value─┐
│ 2020-09-05 │ 2020-09-05 15:56:30 │ CPUFrequencyMHz_0 │ 2120.9 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.arenas.all.pmuzzy │ 743 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.arenas.all.pdirty │ 26288 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.background_thread.run_intervals │ 0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.background_thread.num_runs │ 0 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.retained │ 60694528 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.mapped │ 303161344 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.resident │ 260931584 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.metadata │ 12079488 │
│ 2020-09-05 │ 2020-09-05 15:56:30 │ jemalloc.allocated │ 133756128 │
└────────────┴─────────────────────┴──────────────────────────────────────────┴───────────┘
```
**See Also**
- [system.asynchronous_metrics](../system-tables/asynchronous_metrics.md) — Contains metrics, calculated periodically in the background.
- [system.metric_log](../system-tables/metric_log.md) — Contains history of metrics values from tables `system.metrics` and `system.events`, periodically flushed to disk.