Help Center/ Data Lake Insight/ Spark SQL Syntax Reference/ Built-In Functions/ Aggregate Functions/ var_samp
Updated on 2023-11-03 GMT+08:00
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var_samp

This function is used to return the sample variance of a specified column.

Syntax

var_samp(col)

Parameters

Table 1 Parameter

Parameter

Mandatory

Description

col

Yes

Columns with a data type of numeric.

If the values are of any other type, NULL is returned.

Return Values

The return value is of the DOUBLE type.

Example Code

  • Calculates the sample variance of all offering inventories (items). An example command is as follows: 
    select var_samp(items) from warehouse;

    The command output is as follows:

    _c0        
294.342355
  • When used with group by, it groups all offerings by warehouse (warehourseId) and returns the sample variance of the offering inventory (items) in the same group. An example command is as follows: 
    select warehourseId, var_samp(items) from warehourse group by warehourseId;

    The command output is as follows:

    warehouseId _c1        
city1    18.23124   
city2    16.23344   
city3    11.43425
Parent topic: Aggregate Functions