Add stddevSampStable and small updates to others

docs/en/sql-reference/aggregate-functions/reference/index.md

@@ -16,7 +16,9 @@ Standard aggregate functions:
 - [avg](/docs/en/sql-reference/aggregate-functions/reference/avg.md)
 - [any](/docs/en/sql-reference/aggregate-functions/reference/any.md)
 - [stddevPop](/docs/en/sql-reference/aggregate-functions/reference/stddevpop.md)
+- [stddevPopStable](/docs/en/sql-reference/aggregate-functions/reference/stddevpopstable.md)
 - [stddevSamp](/docs/en/sql-reference/aggregate-functions/reference/stddevsamp.md)
+- [stddevSampStable](/docs/en/sql-reference/aggregate-functions/reference/stddevsampstable.md)
 - [varPop](/docs/en/sql-reference/aggregate-functions/reference/varpop.md)
 - [varSamp](/docs/en/sql-reference/aggregate-functions/reference/varsamp.md)
 - [corr](./corr.md)

docs/en/sql-reference/aggregate-functions/reference/stddevpop.md

@@ -7,9 +7,7 @@ sidebar_position: 30
 
 The result is equal to the square root of [varPop](../../../sql-reference/aggregate-functions/reference/varpop.md).
 
-Alias:
-- `STD`
-- `STDDEV_POP`
+Aliases: `STD`, `STDDEV_POP`.
 
 :::note
 This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the [`stddevPopStable`](../reference/stddevpopstable.md) function. It works slower but provides a lower computational error.
@@ -27,7 +25,7 @@ stddevPop(x)
 
 **Returned value**
 
-Standard deviation of `x`. [Float64](../../data-types/float.md).
+Square root of standard deviation of `x`. [Float64](../../data-types/float.md).
 
 **Example**
 

docs/en/sql-reference/aggregate-functions/reference/stddevpopstable.md

@@ -7,10 +7,6 @@ sidebar_position: 30
 
 The result is equal to the square root of [varPop](../../../sql-reference/aggregate-functions/reference/varpop.md). Unlike [`stddevPop`](../reference/stddevpop.md), this function uses a numerically stable algorithm. It works slower but provides a lower computational error.
 
-:::note
-This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the `stddevPopStable` function. It works slower but provides a lower computational error.
-:::
-
 **Syntax**
 
 ```sql
@@ -23,7 +19,7 @@ stddevPopStable(x)
 
 **Returned value**
 
-Standard deviation of `x`. [Float64](../../data-types/float.md).
+Square root of standard deviation of `x`. [Float64](../../data-types/float.md).
 
 **Example**
 

docs/en/sql-reference/aggregate-functions/reference/stddevsamp.md

@@ -10,5 +10,46 @@ The result is equal to the square root of [varSamp](../../../sql-reference/aggre
 Alias: `STDDEV_SAMP`.
 
 :::note
-This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the `stddevSampStable` function. It works slower but provides a lower computational error.
-:::
+This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the [`stddevSampStable`](../reference/stddevsampstable.md) function. It works slower but provides a lower computational error.
+:::
+
+**Syntax**
+
+```sql
+stddevSamp(x)
+```
+
+**Parameters**
+
+- `x`: Values for which to find the square root of sample variance. [(U)Int*](../../data-types/int-uint.md), [Float*](../../data-types/float.md), [Decimal*](../../data-types/decimal.md).
+
+**Returned value**
+
+Square root of sample variance of `x`. [Float64](../../data-types/float.md).
+
+**Example**
+
+Query:
+
+```sql
+DROP TABLE IF EXISTS test_data;
+CREATE TABLE test_data
+(
+    population UInt8,
+)
+ENGINE = Log;
+
+INSERT INTO test_data VALUES (3),(3),(3),(4),(4),(5),(5),(7),(11),(15);
+
+SELECT
+    stddevSamp(population)
+FROM test_data;
+```
+
+Result:
+
+```response
+┌─stddevSamp(population)─┐
+│                      4 │
+└────────────────────────┘
+```

docs/en/sql-reference/aggregate-functions/reference/stddevsampstable.md

@@ -0,0 +1,49 @@
+---
+slug: /en/sql-reference/aggregate-functions/reference/stddevsampstable
+sidebar_position: 31
+---
+
+# stddevSampStable
+
+The result is equal to the square root of [varSamp](../../../sql-reference/aggregate-functions/reference/varsamp.md). Unlike [`stddevSamp`](../reference/stddevsamp.md) This function uses a numerically stable algorithm. It works slower but provides a lower computational error.
+
+**Syntax**
+
+```sql
+stddevSampStable(x)
+```
+
+**Parameters**
+
+- `x`: Values for which to find the square root of sample variance. [(U)Int*](../../data-types/int-uint.md), [Float*](../../data-types/float.md), [Decimal*](../../data-types/decimal.md).
+
+**Returned value**
+
+Square root of sample variance of `x`. [Float64](../../data-types/float.md).
+
+**Example**
+
+Query:
+
+```sql
+DROP TABLE IF EXISTS test_data;
+CREATE TABLE test_data
+(
+    population UInt8,
+)
+ENGINE = Log;
+
+INSERT INTO test_data VALUES (3),(3),(3),(4),(4),(5),(5),(7),(11),(15);
+
+SELECT
+    stddevSampStable(population)
+FROM test_data;
+```
+
+Result:
+
+```response
+┌─stddevSampStable(population)─┐
+│                            4 │
+└──────────────────────────────┘
+```