Reference material for VAR_SAMP
Computes the sample variance of all non-NULL
numeric values produced by an expression. The sample variance measures the average of the squared differences from the sample mean, indicating how spread out the values are within a sample.
For information about the population variance, which measures how spread out the values are within the full population, see VAR_POP.
Alias: VARIANCE
Parameter | Description | Supported input types |
---|---|---|
<expression> | An expression producing numeric values for which to calculate the sample variance. | REAL , DOUBLE PRECISION |
VAR_SAMP
returns a result of type DOUBLE PRECISION
.
NULL
input value, the result is NULL
.Inf
or NaN
value, the result will be NaN
.The following code creates an exams
table with a grade
column of type DOUBLE PRECISION
, and inserts five grade values into it:
The following code calculates the sample variance of the grade values from the exams
table, rounds the result to three decimal places, and returns it as variance
:
Returns The previous code returns the following result:
variance (DOUBLE PRECISION) |
---|
0.342 |