Reference material for STDDEV_POP
Computes the population standard deviation of all non-NULL
numeric values produced by an expression. The population standard deviation shows how spread out the values in a population are, by measuring the average distance of each value from the population’s mean.
For information about the sample standard deviation, which estimates the spread of values across sample rather than the full population, see STDDEV_SAMP.
Parameter | Description | Supported input types |
---|---|---|
<expression> | An expression producing numeric values for which to calculate the population standard deviation. | REAL , DOUBLE PRECISION |
STDDEV_POP
returns a result of type DOUBLE PRECISION
.
NULL
input values, 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 population standard deviation of the grade values from the exams
table, rounds the result to three decimal places, and returns it as stddev
:
Returns The previous code returns the following result:
stddev (DOUBLE PRECISION) |
---|
0.523 |
Reference material for STDDEV_POP
Computes the population standard deviation of all non-NULL
numeric values produced by an expression. The population standard deviation shows how spread out the values in a population are, by measuring the average distance of each value from the population’s mean.
For information about the sample standard deviation, which estimates the spread of values across sample rather than the full population, see STDDEV_SAMP.
Parameter | Description | Supported input types |
---|---|---|
<expression> | An expression producing numeric values for which to calculate the population standard deviation. | REAL , DOUBLE PRECISION |
STDDEV_POP
returns a result of type DOUBLE PRECISION
.
NULL
input values, 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 population standard deviation of the grade values from the exams
table, rounds the result to three decimal places, and returns it as stddev
:
Returns The previous code returns the following result:
stddev (DOUBLE PRECISION) |
---|
0.523 |