ClickHouse/docs/en/operations/system-tables/query_log_metric.md

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---
slug: /en/operations/system-tables/query_log_metric
---
2024-07-18 10:29:03 +00:00
# query_log_metric
Contains history of memory and metric values from table `system.events` for individual queries, periodically flushed to disk.
Once a query starts, data is collected at periodic intervals of `query_log_metric_interval` milliseconds (which is set to 1000
by default) and when the query finishes.
Columns:
- `hostname` ([LowCardinality(String)](../../sql-reference/data-types/string.md)) — Hostname of the server executing the query.
- `event_date` ([Date](../../sql-reference/data-types/date.md)) — Event date.
- `event_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — Event time.
- `event_time_microseconds` ([DateTime64](../../sql-reference/data-types/datetime64.md)) — Event time with microseconds resolution.
- `query_id` ([String](../../sql-reference/data-types/string.md)) — ID of the query.
**Example**
``` sql
SELECT * FROM system.query_log_metric LIMIT 1 FORMAT Vertical;
```
``` text
Row 1:
──────
hostname: clickhouse.eu-central1.internal
event_date: 2020-09-05
event_time: 2020-09-05 16:22:33
event_time_microseconds: 2020-09-05 16:22:33.196807
CurrentMetric_MemoryTracking: 480794407
CurrentMetric_MergesMutationsMemoryTracking: 0
ProfileEvent_Query: 0
ProfileEvent_SelectQuery: 0
ProfileEvent_InsertQuery: 0
ProfileEvent_FailedQuery: 0
ProfileEvent_FailedSelectQuery: 0
...
```
**See also**
- [query_log_metric setting](../../operations/server-configuration-parameters/settings.md#query_log_metric) — Enabling and disabling the setting.
- [query_log_metric_interval](../../operations/settings/settings.md#query_log_metric_interval)
- [system.asynchronous_metrics](../../operations/system-tables/asynchronous_metrics.md) — Contains periodically calculated metrics.
- [system.events](../../operations/system-tables/events.md#system_tables-events) — Contains a number of events that occurred.
- [system.metrics](../../operations/system-tables/metrics.md) — Contains instantly calculated metrics.
- [Monitoring](../../operations/monitoring.md) — Base concepts of ClickHouse monitoring.