diff --git a/system-variables.md b/system-variables.md index c6c7c9171fc6b..d0d02b98e9e38 100644 --- a/system-variables.md +++ b/system-variables.md @@ -5264,7 +5264,7 @@ Query OK, 0 rows affected, 1 warning (0.00 sec) - Default value: `300` - Range: `[-1, 9223372036854775807]` - Unit: Milliseconds -- This variable is used to output the threshold value of the time consumed by the slow log. When the time consumed by a query is larger than this value, this query is considered as a slow log and its log is output to the slow query log. +- This variable outputs the threshold value of the time consumed by the slow log, and is set to 300 milliseconds by default. When the time consumed by a query is larger than this value, this query is considered as a slow query and its log is output to the slow query log. Note that when the output level of [`log.level`](https://docs.pingcap.com/tidb/dev/tidb-configuration-file#level) is `"debug"`, all queries are recorded in the slow query log, regardless of the setting of this variable. ### tidb_slow_query_file diff --git a/tidb-configuration-file.md b/tidb-configuration-file.md index e8a6a80df4ecc..12cf88fd9132d 100644 --- a/tidb-configuration-file.md +++ b/tidb-configuration-file.md @@ -309,7 +309,7 @@ Configuration items related to log. - Outputs the threshold value of consumed time in the slow log. - Default value: `300` - Unit: Milliseconds -- If the value in a query is larger than the default value, it is a slow query and is output to the slow log. +- When the time consumed by a query is larger than this value, this query is considered as a slow query and its log is output to the slow query log. Note that when the output level of [`log.level`](#level) is `"debug"`, all queries are recorded in the slow query log, regardless of the setting of this parameter. - Since v6.1.0, the threshold value of consumed time in the slow log is specified by the TiDB configuration item [`instance.tidb_slow_log_threshold`](/tidb-configuration-file.md#tidb_slow_log_threshold) or the system variable [`tidb_slow_log_threshold`](/system-variables.md#tidb_slow_log_threshold). `slow-threshold` still takes effect. But if `slow-threshold` and `instance.tidb_slow_log_threshold` are set at the same time, the latter takes effect. ### `record-plan-in-slow-log` @@ -904,10 +904,11 @@ Configuration items related to read isolation. ### `tidb_slow_log_threshold` -- This configuration is used to output the threshold value of the time consumed by the slow log. When the time consumed by a query is larger than this value, this query is considered as a slow log and its log is output to the slow query log. +- Outputs the threshold value of the time consumed by the slow log. - Default value: `300` - Range: `[-1, 9223372036854775807]` - Unit: Milliseconds +- When the time consumed by a query is larger than this value, this query is considered as a slow query and its log is output to the slow query log. Note that when the output level of [`log.level`](#level) is `"debug"`, all queries are recorded in the slow query log, regardless of the setting of this parameter. - Before v6.1.0, this configuration is set by `slow-threshold`. ### `in-mem-slow-query-topn-num` New in v7.3.0