percentile

This function is used to return the numerical value at a certain percentage point within a range of values.

Syntax

percentile(BIGINT col, p)

Parameters

**Table 1** Parameters
Parameter	Mandatory	Description
col	Yes	Columns with a data type of numeric. If the values are of any other type, NULL is returned.
p	Yes	The value should be between 0 and 1. Otherwise, NULL is returned.

Return Values

The return value is of the DOUBLE type.

The value should be between 0 and 1. Otherwise, NULL is returned.

Example Code

Calculates the 0.5 percentile of all offering inventories (items). An example command is as follows:
```
select stddev_samp(items,0.5) from warehouse; 
```
The command output is as follows:
```
_c0        
500.6      
```
When used with group by, it groups all offerings by warehouse (warehourseId) and returns the 0.5 percentile of the offering inventory (items) in the same group. An example command is as follows:
```
select warehourseId, stddev_samp(items, 0.5) from warehourse group by warehourseId; 
```
The command output is as follows:
```
warehouseId _c1        
city1    499.6      
city2    354.8      
city3    565.7      
```

Parent topic: Aggregate Functions