diff --git a/src/UserGuide/Master/Reference/Function-and-Expression.md b/src/UserGuide/Master/Reference/Function-and-Expression.md
index 045646183..8fba38ac7 100644
--- a/src/UserGuide/Master/Reference/Function-and-Expression.md
+++ b/src/UserGuide/Master/Reference/Function-and-Expression.md
@@ -549,6 +549,7 @@ The aggregate functions supported by IoTDB are as follows:
| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 |
| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 |
| MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type |
+| STDDEV | Calculate the overall standard deviation of the data. Note:
Missing points, null points and `NaN` in the input series will be ignored.| INT32 INT64 FLOAT DOUBLE | / | DOUBLE |
| COUNT_TIME | The number of timestamps in the query data set. When used with `align by device`, the result is the number of timestamps in the data set per device. | All data Types, the input parameter can only be `*` | / | INT64 |
diff --git a/src/UserGuide/Master/Reference/UDF-Libraries.md b/src/UserGuide/Master/Reference/UDF-Libraries.md
index e3364d513..9649c0f27 100644
--- a/src/UserGuide/Master/Reference/UDF-Libraries.md
+++ b/src/UserGuide/Master/Reference/UDF-Libraries.md
@@ -1140,60 +1140,6 @@ Output series:
+-----------------------------+--------------------+
```
-### Mode
-
-#### Usage
-
-This function is used to calculate the mode of time series, that is, the value that occurs most frequently.
-
-**Name:** MODE
-
-**Input Series:** Only support a single input series. The type is arbitrary.
-
-**Output Series:** Output a single series. The type is the same as the input. There is only one data point in the series, whose timestamp is the same as which the first mode value has and value is the mode.
-
-**Note:**
-
-+ If there are multiple values with the most occurrences, the arbitrary one will be output.
-+ Missing points and null points in the input series will be ignored, but `NaN` will not.
-
-#### Examples
-
-Input series:
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d2.s2|
-+-----------------------------+---------------+
-|1970-01-01T08:00:00.001+08:00| Hello|
-|1970-01-01T08:00:00.002+08:00| hello|
-|1970-01-01T08:00:00.003+08:00| Hello|
-|1970-01-01T08:00:00.004+08:00| World|
-|1970-01-01T08:00:00.005+08:00| World|
-|1970-01-01T08:00:01.600+08:00| World|
-|1970-01-15T09:37:34.451+08:00| Hello|
-|1970-01-15T09:37:34.452+08:00| hello|
-|1970-01-15T09:37:34.453+08:00| Hello|
-|1970-01-15T09:37:34.454+08:00| World|
-|1970-01-15T09:37:34.455+08:00| World|
-+-----------------------------+---------------+
-```
-
-SQL for query:
-
-```sql
-select mode(s2) from root.test.d2
-```
-
-Output series:
-
-```
-+-----------------------------+---------------------+
-| Time|mode(root.test.d2.s2)|
-+-----------------------------+---------------------+
-|1970-01-01T08:00:00.004+08:00| World|
-+-----------------------------+---------------------+
-```
### MvAvg
@@ -2264,66 +2210,7 @@ Output series:
+-----------------------------+-----------------------+
```
-### Stddev
-
-#### Usage
-
-This function is used to calculate the population standard deviation.
-
-**Name:** STDDEV
-
-**Input Series:** Only support a single input series. The type is INT32 / INT64 / FLOAT / DOUBLE.
-
-**Output Series:** Output a single series. The type is DOUBLE. There is only one data point in the series, whose timestamp is 0 and value is the population standard deviation.
-
-**Note:** Missing points, null points and `NaN` in the input series will be ignored.
-
-#### Examples
-
-Input series:
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d1.s1|
-+-----------------------------+---------------+
-|2020-01-01T00:00:00.000+08:00| 1.0|
-|2020-01-01T00:00:01.000+08:00| 2.0|
-|2020-01-01T00:00:02.000+08:00| 3.0|
-|2020-01-01T00:00:03.000+08:00| 4.0|
-|2020-01-01T00:00:04.000+08:00| 5.0|
-|2020-01-01T00:00:05.000+08:00| 6.0|
-|2020-01-01T00:00:06.000+08:00| 7.0|
-|2020-01-01T00:00:07.000+08:00| 8.0|
-|2020-01-01T00:00:08.000+08:00| 9.0|
-|2020-01-01T00:00:09.000+08:00| 10.0|
-|2020-01-01T00:00:10.000+08:00| 11.0|
-|2020-01-01T00:00:11.000+08:00| 12.0|
-|2020-01-01T00:00:12.000+08:00| 13.0|
-|2020-01-01T00:00:13.000+08:00| 14.0|
-|2020-01-01T00:00:14.000+08:00| 15.0|
-|2020-01-01T00:00:15.000+08:00| 16.0|
-|2020-01-01T00:00:16.000+08:00| 17.0|
-|2020-01-01T00:00:17.000+08:00| 18.0|
-|2020-01-01T00:00:18.000+08:00| 19.0|
-|2020-01-01T00:00:19.000+08:00| 20.0|
-+-----------------------------+---------------+
-```
-
-SQL for query:
-```sql
-select stddev(s1) from root.test.d1
-```
-
-Output series:
-
-```
-+-----------------------------+-----------------------+
-| Time|stddev(root.test.d1.s1)|
-+-----------------------------+-----------------------+
-|1970-01-01T08:00:00.000+08:00| 5.7662812973353965|
-+-----------------------------+-----------------------+
-```
### ZScore
diff --git a/src/UserGuide/latest/Reference/Function-and-Expression.md b/src/UserGuide/latest/Reference/Function-and-Expression.md
index 045646183..8fba38ac7 100644
--- a/src/UserGuide/latest/Reference/Function-and-Expression.md
+++ b/src/UserGuide/latest/Reference/Function-and-Expression.md
@@ -549,6 +549,7 @@ The aggregate functions supported by IoTDB are as follows:
| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 |
| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 |
| MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type |
+| STDDEV | Calculate the overall standard deviation of the data. Note:
Missing points, null points and `NaN` in the input series will be ignored.| INT32 INT64 FLOAT DOUBLE | / | DOUBLE |
| COUNT_TIME | The number of timestamps in the query data set. When used with `align by device`, the result is the number of timestamps in the data set per device. | All data Types, the input parameter can only be `*` | / | INT64 |
diff --git a/src/UserGuide/latest/Reference/UDF-Libraries.md b/src/UserGuide/latest/Reference/UDF-Libraries.md
index 0295dfe7b..fd7422d8f 100644
--- a/src/UserGuide/latest/Reference/UDF-Libraries.md
+++ b/src/UserGuide/latest/Reference/UDF-Libraries.md
@@ -1140,60 +1140,7 @@ Output series:
+-----------------------------+--------------------+
```
-### Mode
-#### Usage
-
-This function is used to calculate the mode of time series, that is, the value that occurs most frequently.
-
-**Name:** MODE
-
-**Input Series:** Only support a single input series. The type is arbitrary.
-
-**Output Series:** Output a single series. The type is the same as the input. There is only one data point in the series, whose timestamp is the same as which the first mode value has and value is the mode.
-
-**Note:**
-
-+ If there are multiple values with the most occurrences, the arbitrary one will be output.
-+ Missing points and null points in the input series will be ignored, but `NaN` will not.
-
-#### Examples
-
-Input series:
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d2.s2|
-+-----------------------------+---------------+
-|1970-01-01T08:00:00.001+08:00| Hello|
-|1970-01-01T08:00:00.002+08:00| hello|
-|1970-01-01T08:00:00.003+08:00| Hello|
-|1970-01-01T08:00:00.004+08:00| World|
-|1970-01-01T08:00:00.005+08:00| World|
-|1970-01-01T08:00:01.600+08:00| World|
-|1970-01-15T09:37:34.451+08:00| Hello|
-|1970-01-15T09:37:34.452+08:00| hello|
-|1970-01-15T09:37:34.453+08:00| Hello|
-|1970-01-15T09:37:34.454+08:00| World|
-|1970-01-15T09:37:34.455+08:00| World|
-+-----------------------------+---------------+
-```
-
-SQL for query:
-
-```sql
-select mode(s2) from root.test.d2
-```
-
-Output series:
-
-```
-+-----------------------------+---------------------+
-| Time|mode(root.test.d2.s2)|
-+-----------------------------+---------------------+
-|1970-01-01T08:00:00.004+08:00| World|
-+-----------------------------+---------------------+
-```
### MvAvg
@@ -2264,66 +2211,6 @@ Output series:
+-----------------------------+-----------------------+
```
-### Stddev
-
-#### Usage
-
-This function is used to calculate the population standard deviation.
-
-**Name:** STDDEV
-
-**Input Series:** Only support a single input series. The type is INT32 / INT64 / FLOAT / DOUBLE.
-
-**Output Series:** Output a single series. The type is DOUBLE. There is only one data point in the series, whose timestamp is 0 and value is the population standard deviation.
-
-**Note:** Missing points, null points and `NaN` in the input series will be ignored.
-
-#### Examples
-
-Input series:
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d1.s1|
-+-----------------------------+---------------+
-|2020-01-01T00:00:00.000+08:00| 1.0|
-|2020-01-01T00:00:01.000+08:00| 2.0|
-|2020-01-01T00:00:02.000+08:00| 3.0|
-|2020-01-01T00:00:03.000+08:00| 4.0|
-|2020-01-01T00:00:04.000+08:00| 5.0|
-|2020-01-01T00:00:05.000+08:00| 6.0|
-|2020-01-01T00:00:06.000+08:00| 7.0|
-|2020-01-01T00:00:07.000+08:00| 8.0|
-|2020-01-01T00:00:08.000+08:00| 9.0|
-|2020-01-01T00:00:09.000+08:00| 10.0|
-|2020-01-01T00:00:10.000+08:00| 11.0|
-|2020-01-01T00:00:11.000+08:00| 12.0|
-|2020-01-01T00:00:12.000+08:00| 13.0|
-|2020-01-01T00:00:13.000+08:00| 14.0|
-|2020-01-01T00:00:14.000+08:00| 15.0|
-|2020-01-01T00:00:15.000+08:00| 16.0|
-|2020-01-01T00:00:16.000+08:00| 17.0|
-|2020-01-01T00:00:17.000+08:00| 18.0|
-|2020-01-01T00:00:18.000+08:00| 19.0|
-|2020-01-01T00:00:19.000+08:00| 20.0|
-+-----------------------------+---------------+
-```
-
-SQL for query:
-
-```sql
-select stddev(s1) from root.test.d1
-```
-
-Output series:
-
-```
-+-----------------------------+-----------------------+
-| Time|stddev(root.test.d1.s1)|
-+-----------------------------+-----------------------+
-|1970-01-01T08:00:00.000+08:00| 5.7662812973353965|
-+-----------------------------+-----------------------+
-```
### ZScore
diff --git a/src/zh/UserGuide/Master/Reference/Function-and-Expression.md b/src/zh/UserGuide/Master/Reference/Function-and-Expression.md
index f64b545f1..8775e99f7 100644
--- a/src/zh/UserGuide/Master/Reference/Function-and-Expression.md
+++ b/src/zh/UserGuide/Master/Reference/Function-and-Expression.md
@@ -44,6 +44,7 @@ IoTDB 支持的聚合函数如下：
| COUNT_IF | 求数据点连续满足某一给定条件，且满足条件的数据点个数（用keep表示）满足指定阈值的次数。 | BOOLEAN | `[keep >=/>/=/!=/= threshold`,`threshold`类型为`INT64`
`ignoreNull`：可选，默认为`true`；为`true`表示忽略null值，即如果中间出现null值，直接忽略，不会打断连续性；为`false`表示不忽略null值，即如果中间出现null值，会打断连续性 | INT64 |
| TIME_DURATION | 求某一列最大一个不为NULL的值所在时间戳与最小一个不为NULL的值所在时间戳的时间戳差 | 所有类型 | 无 | INT64 |
| MODE | 求众数。注意：
1.输入序列的不同值个数过多时会有内存异常风险;
2.如果所有元素出现的频次相同，即没有众数，则返回对应时间戳最小的值;
3.如果有多个众数，则返回对应时间戳最小的众数。 | 所有类型 | 无 | 与输入类型一致 |
+| STDDEV | 求数据的总体标准差。注意：
数据中的空值、缺失值和`NaN`将会被忽略。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE |
| COUNT_TIME | 查询结果集的时间戳的数量。与 align by device 搭配使用时，得到的结果是每个设备的结果集的时间戳的数量。 | 所有类型，输入参数只能为* | 无 | INT64 |
| MAX_BY | MAX_BY(x, y) 求二元输入 x 和 y 在 y 最大时对应的 x 的值。MAX_BY(time, x) 返回 x 取最大值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 |
| MIN_BY | MIN_BY(x, y) 求二元输入 x 和 y 在 y 最小时对应的 x 的值。MIN_BY(time, x) 返回 x 取最小值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 |
diff --git a/src/zh/UserGuide/Master/Reference/UDF-Libraries.md b/src/zh/UserGuide/Master/Reference/UDF-Libraries.md
index cbd829937..9b1e7c1ff 100644
--- a/src/zh/UserGuide/Master/Reference/UDF-Libraries.md
+++ b/src/zh/UserGuide/Master/Reference/UDF-Libraries.md
@@ -1143,60 +1143,7 @@ select minmax(s1) from root.test
+-----------------------------+--------------------+
```
-### Mode
-#### 函数简介
-
-本函数用于计算时间序列的众数，即出现次数最多的元素。
-
-**函数名：** MODE
-
-**输入序列：** 仅支持单个输入序列，类型可以是任意的。
-
-**输出序列：** 输出单个序列，类型与输入相同，序列仅包含一个时间戳为众数第一次出现的时间戳、值为众数的数据点。
-
-**提示：**
-
-+ 如果有多个出现次数最多的元素，将会输出任意一个。
-+ 数据中的空值和缺失值将会被忽略，但`NaN`不会被忽略。
-
-#### 使用示例
-
-输入序列：
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d2.s2|
-+-----------------------------+---------------+
-|1970-01-01T08:00:00.001+08:00| Hello|
-|1970-01-01T08:00:00.002+08:00| hello|
-|1970-01-01T08:00:00.003+08:00| Hello|
-|1970-01-01T08:00:00.004+08:00| World|
-|1970-01-01T08:00:00.005+08:00| World|
-|1970-01-01T08:00:01.600+08:00| World|
-|1970-01-15T09:37:34.451+08:00| Hello|
-|1970-01-15T09:37:34.452+08:00| hello|
-|1970-01-15T09:37:34.453+08:00| Hello|
-|1970-01-15T09:37:34.454+08:00| World|
-|1970-01-15T09:37:34.455+08:00| World|
-+-----------------------------+---------------+
-```
-
-用于查询的 SQL 语句：
-
-```sql
-select mode(s2) from root.test.d2
-```
-
-输出序列：
-
-```
-+-----------------------------+---------------------+
-| Time|mode(root.test.d2.s2)|
-+-----------------------------+---------------------+
-|1970-01-01T08:00:00.004+08:00| World|
-+-----------------------------+---------------------+
-```
### MvAvg
@@ -2256,66 +2203,7 @@ select spread(s1) from root.test.d1 where time <= 2020-01-01 00:00:30
+-----------------------------+-----------------------+
```
-### Stddev
-
-#### 函数简介
-
-本函数用于计算单列数值型数据的总体标准差。
-
-**函数名：** STDDEV
-
-**输入序列：** 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE。
-
-**输出序列：** 输出单个序列，类型为 DOUBLE。序列仅包含一个时间戳为 0、值为总体标准差的数据点。
-
-**提示：** 数据中的空值、缺失值和`NaN`将会被忽略。
-
-#### 使用示例
-
-输入序列：
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d1.s1|
-+-----------------------------+---------------+
-|2020-01-01T00:00:00.000+08:00| 1.0|
-|2020-01-01T00:00:01.000+08:00| 2.0|
-|2020-01-01T00:00:02.000+08:00| 3.0|
-|2020-01-01T00:00:03.000+08:00| 4.0|
-|2020-01-01T00:00:04.000+08:00| 5.0|
-|2020-01-01T00:00:05.000+08:00| 6.0|
-|2020-01-01T00:00:06.000+08:00| 7.0|
-|2020-01-01T00:00:07.000+08:00| 8.0|
-|2020-01-01T00:00:08.000+08:00| 9.0|
-|2020-01-01T00:00:09.000+08:00| 10.0|
-|2020-01-01T00:00:10.000+08:00| 11.0|
-|2020-01-01T00:00:11.000+08:00| 12.0|
-|2020-01-01T00:00:12.000+08:00| 13.0|
-|2020-01-01T00:00:13.000+08:00| 14.0|
-|2020-01-01T00:00:14.000+08:00| 15.0|
-|2020-01-01T00:00:15.000+08:00| 16.0|
-|2020-01-01T00:00:16.000+08:00| 17.0|
-|2020-01-01T00:00:17.000+08:00| 18.0|
-|2020-01-01T00:00:18.000+08:00| 19.0|
-|2020-01-01T00:00:19.000+08:00| 20.0|
-+-----------------------------+---------------+
-```
-
-用于查询的 SQL 语句：
-
-```sql
-select stddev(s1) from root.test.d1
-```
-
-输出序列：
-```
-+-----------------------------+-----------------------+
-| Time|stddev(root.test.d1.s1)|
-+-----------------------------+-----------------------+
-|1970-01-01T08:00:00.000+08:00| 5.7662812973353965|
-+-----------------------------+-----------------------+
-```
### ZScore
diff --git a/src/zh/UserGuide/latest/Reference/Function-and-Expression.md b/src/zh/UserGuide/latest/Reference/Function-and-Expression.md
index 6efcf9f58..816ebb0c5 100644
--- a/src/zh/UserGuide/latest/Reference/Function-and-Expression.md
+++ b/src/zh/UserGuide/latest/Reference/Function-and-Expression.md
@@ -43,7 +43,8 @@ IoTDB 支持的聚合函数如下：
| MIN_TIME | 求最小时间戳。 | 所有类型 | 无 | Timestamp |
| COUNT_IF | 求数据点连续满足某一给定条件，且满足条件的数据点个数（用keep表示）满足指定阈值的次数。 | BOOLEAN | `[keep >=/>/=/!=/= threshold`,`threshold`类型为`INT64`
`ignoreNull`：可选，默认为`true`；为`true`表示忽略null值，即如果中间出现null值，直接忽略，不会打断连续性；为`false`表示不忽略null值，即如果中间出现null值，会打断连续性 | INT64 |
| TIME_DURATION | 求某一列最大一个不为NULL的值所在时间戳与最小一个不为NULL的值所在时间戳的时间戳差 | 所有类型 | 无 | INT64 |
-| MODE | 求众数。注意：
1.输入序列的不同值个数过多时会有内存异常风险;
2.如果所有元素出现的频次相同，即没有众数，则返回对应时间戳最小的值;
3.如果有多个众数，则返回对应时间戳最小的众数。 | 所有类型 | 无 | 与输入类型一致 |
+| MODE | 求众数。注意：
1.输入序列的不同值个数过多时会有内存异常风险;
2.如果所有元素出现的频次相同，即没有众数，则返回对应时间戳最小的值;
3.如果有多个众数，则返回对应时间戳最小的众数。 | 所有类型 | 无 | 与输入类型一致 |
+| STDDEV | 求数据的总体标准差。注意：
数据中的空值、缺失值和`NaN`将会被忽略。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE |
| COUNT_TIME | 查询结果集的时间戳的数量。与 align by device 搭配使用时，得到的结果是每个设备的结果集的时间戳的数量。 | 所有类型，输入参数只能为* | 无 | INT64 |
| MAX_BY | MAX_BY(x, y) 求二元输入 x 和 y 在 y 最大时对应的 x 的值。MAX_BY(time, x) 返回 x 取最大值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 |
| MIN_BY | MIN_BY(x, y) 求二元输入 x 和 y 在 y 最小时对应的 x 的值。MIN_BY(time, x) 返回 x 取最小值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 |
diff --git a/src/zh/UserGuide/latest/Reference/UDF-Libraries.md b/src/zh/UserGuide/latest/Reference/UDF-Libraries.md
index e587777eb..e1f81a823 100644
--- a/src/zh/UserGuide/latest/Reference/UDF-Libraries.md
+++ b/src/zh/UserGuide/latest/Reference/UDF-Libraries.md
@@ -1144,60 +1144,6 @@ select minmax(s1) from root.test
+-----------------------------+--------------------+
```
-### Mode
-
-#### 函数简介
-
-本函数用于计算时间序列的众数，即出现次数最多的元素。
-
-**函数名：** MODE
-
-**输入序列：** 仅支持单个输入序列，类型可以是任意的。
-
-**输出序列：** 输出单个序列，类型与输入相同，序列仅包含一个时间戳为众数第一次出现的时间戳、值为众数的数据点。
-
-**提示：**
-
-+ 如果有多个出现次数最多的元素，将会输出任意一个。
-+ 数据中的空值和缺失值将会被忽略，但`NaN`不会被忽略。
-
-#### 使用示例
-
-输入序列：
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d2.s2|
-+-----------------------------+---------------+
-|1970-01-01T08:00:00.001+08:00| Hello|
-|1970-01-01T08:00:00.002+08:00| hello|
-|1970-01-01T08:00:00.003+08:00| Hello|
-|1970-01-01T08:00:00.004+08:00| World|
-|1970-01-01T08:00:00.005+08:00| World|
-|1970-01-01T08:00:01.600+08:00| World|
-|1970-01-15T09:37:34.451+08:00| Hello|
-|1970-01-15T09:37:34.452+08:00| hello|
-|1970-01-15T09:37:34.453+08:00| Hello|
-|1970-01-15T09:37:34.454+08:00| World|
-|1970-01-15T09:37:34.455+08:00| World|
-+-----------------------------+---------------+
-```
-
-用于查询的 SQL 语句：
-
-```sql
-select mode(s2) from root.test.d2
-```
-
-输出序列：
-
-```
-+-----------------------------+---------------------+
-| Time|mode(root.test.d2.s2)|
-+-----------------------------+---------------------+
-|1970-01-01T08:00:00.004+08:00| World|
-+-----------------------------+---------------------+
-```
### MvAvg
@@ -2257,66 +2203,6 @@ select spread(s1) from root.test.d1 where time <= 2020-01-01 00:00:30
+-----------------------------+-----------------------+
```
-### Stddev
-
-#### 函数简介
-
-本函数用于计算单列数值型数据的总体标准差。
-
-**函数名：** STDDEV
-
-**输入序列：** 仅支持单个输入序列，类型为 INT32 / INT64 / FLOAT / DOUBLE。
-
-**输出序列：** 输出单个序列，类型为 DOUBLE。序列仅包含一个时间戳为 0、值为总体标准差的数据点。
-
-**提示：** 数据中的空值、缺失值和`NaN`将会被忽略。
-
-#### 使用示例
-
-输入序列：
-
-```
-+-----------------------------+---------------+
-| Time|root.test.d1.s1|
-+-----------------------------+---------------+
-|2020-01-01T00:00:00.000+08:00| 1.0|
-|2020-01-01T00:00:01.000+08:00| 2.0|
-|2020-01-01T00:00:02.000+08:00| 3.0|
-|2020-01-01T00:00:03.000+08:00| 4.0|
-|2020-01-01T00:00:04.000+08:00| 5.0|
-|2020-01-01T00:00:05.000+08:00| 6.0|
-|2020-01-01T00:00:06.000+08:00| 7.0|
-|2020-01-01T00:00:07.000+08:00| 8.0|
-|2020-01-01T00:00:08.000+08:00| 9.0|
-|2020-01-01T00:00:09.000+08:00| 10.0|
-|2020-01-01T00:00:10.000+08:00| 11.0|
-|2020-01-01T00:00:11.000+08:00| 12.0|
-|2020-01-01T00:00:12.000+08:00| 13.0|
-|2020-01-01T00:00:13.000+08:00| 14.0|
-|2020-01-01T00:00:14.000+08:00| 15.0|
-|2020-01-01T00:00:15.000+08:00| 16.0|
-|2020-01-01T00:00:16.000+08:00| 17.0|
-|2020-01-01T00:00:17.000+08:00| 18.0|
-|2020-01-01T00:00:18.000+08:00| 19.0|
-|2020-01-01T00:00:19.000+08:00| 20.0|
-+-----------------------------+---------------+
-```
-
-用于查询的 SQL 语句：
-
-```sql
-select stddev(s1) from root.test.d1
-```
-
-输出序列：
-
-```
-+-----------------------------+-----------------------+
-| Time|stddev(root.test.d1.s1)|
-+-----------------------------+-----------------------+
-|1970-01-01T08:00:00.000+08:00| 5.7662812973353965|
-+-----------------------------+-----------------------+
-```
### ZScore