diff --git a/config/config.md b/config/config.md
index 3d1d6f2ca5f7..5001d42a0105 100644
--- a/config/config.md
+++ b/config/config.md
@@ -166,6 +166,7 @@
 | `logging.slow_query` | -- | -- | The slow query log options. |
 | `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
 | `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
+| `logging.slow_query.sample_rate` | Float | Unset | The sampling rate of slow query log. |
 | `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
 | `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
 | `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
@@ -255,6 +256,7 @@
 | `logging.slow_query` | -- | -- | The slow query log options. |
 | `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
 | `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
+| `logging.slow_query.sample_rate` | Float | Unset | The sampling rate of slow query log. |
 | `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
 | `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
 | `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
@@ -323,6 +325,7 @@
 | `logging.slow_query` | -- | -- | The slow query log options. |
 | `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
 | `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
+| `logging.slow_query.sample_rate` | Float | Unset | The sampling rate of slow query log. |
 | `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
 | `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
 | `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
@@ -478,6 +481,7 @@
 | `logging.slow_query` | -- | -- | The slow query log options. |
 | `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
 | `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
+| `logging.slow_query.sample_rate` | Float | Unset | The sampling rate of slow query log. |
 | `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
 | `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
 | `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
@@ -527,5 +531,6 @@
 | `logging.slow_query` | -- | -- | The slow query log options. |
 | `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
 | `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
+| `logging.slow_query.sample_rate` | Float | Unset | The sampling rate of slow query log. |
 | `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
 | `tracing.tokio_console_addr` | String | Unset | The tokio console address. |
diff --git a/config/datanode.example.toml b/config/datanode.example.toml
index acb4f818f96a..ff019c3876c8 100644
--- a/config/datanode.example.toml
+++ b/config/datanode.example.toml
@@ -595,6 +595,10 @@ enable = false
 ## @toml2docs:none-default
 threshold = "10s"
 
+## The sampling rate of slow query log.
+## @toml2docs:none-default
+sample_rate = 1.0
+
 ## The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.
 ## This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape.
 [export_metrics]
diff --git a/config/flownode.example.toml b/config/flownode.example.toml
index defb5ef1e8d1..2927052ac927 100644
--- a/config/flownode.example.toml
+++ b/config/flownode.example.toml
@@ -93,6 +93,10 @@ enable = false
 ## @toml2docs:none-default
 threshold = "10s"
 
+## The sampling rate of slow query log.
+## @toml2docs:none-default
+sample_rate = 1.0
+
 ## The tracing options. Only effect when compiled with `tokio-console` feature.
 [tracing]
 ## The tokio console address.
diff --git a/config/frontend.example.toml b/config/frontend.example.toml
index 2c6ecd7f53b0..26a88f729dfd 100644
--- a/config/frontend.example.toml
+++ b/config/frontend.example.toml
@@ -200,6 +200,10 @@ enable = false
 ## @toml2docs:none-default
 threshold = "10s"
 
+## The sampling rate of slow query log.
+## @toml2docs:none-default
+sample_rate = 1.0
+
 ## The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.
 ## This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape.
 [export_metrics]
diff --git a/config/metasrv.example.toml b/config/metasrv.example.toml
index f518e7826b2f..6a8412af312d 100644
--- a/config/metasrv.example.toml
+++ b/config/metasrv.example.toml
@@ -187,6 +187,10 @@ enable = false
 ## @toml2docs:none-default
 threshold = "10s"
 
+## The sampling rate of slow query log.
+## @toml2docs:none-default
+sample_rate = 1.0
+
 ## The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.
 ## This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape.
 [export_metrics]
diff --git a/config/standalone.example.toml b/config/standalone.example.toml
index 91a14fe199ca..2838dacd4810 100644
--- a/config/standalone.example.toml
+++ b/config/standalone.example.toml
@@ -639,6 +639,10 @@ enable = false
 ## @toml2docs:none-default
 threshold = "10s"
 
+## The sampling rate of slow query log.
+## @toml2docs:none-default
+sample_rate = 1.0
+
 ## The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.
 ## This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape.
 [export_metrics]