Google Standard SQL for Spanner supports statistical aggregate functions. To learn about the syntax for aggregate function calls, see Aggregate function calls.
STDDEV_SAMP
STDDEV_SAMP(
[ DISTINCT ]
expression
[ HAVING { MAX | MIN } expression2 ]
)
Description
Returns the sample (unbiased) standard deviation of the values. The return
result is between 0 and +Inf.
All numeric types are supported. If the
input is NUMERIC then the internal aggregation is
stable with the final output converted to a FLOAT64.
Otherwise the input is converted to a FLOAT64
before aggregation, resulting in a potentially unstable result.
This function ignores any NULL inputs. If there are fewer than two non-NULL inputs, this function returns NULL.
To learn more about the optional arguments in this function and how to use them, see Aggregate function calls.
Return Data Type
FLOAT64
STDDEV
STDDEV(
[ DISTINCT ]
expression
[ HAVING { MAX | MIN } expression2 ]
)
Description
An alias of STDDEV_SAMP.
VAR_SAMP
VAR_SAMP(
[ DISTINCT ]
expression
[ HAVING { MAX | MIN } expression2 ]
)
Description
Returns the sample (unbiased) variance of the values. The return result is
between 0 and +Inf.
All numeric types are supported. If the
input is NUMERIC then the internal aggregation is
stable with the final output converted to a FLOAT64.
Otherwise the input is converted to a FLOAT64
before aggregation, resulting in a potentially unstable result.
This function ignores any NULL inputs. If there are fewer than two non-NULL inputs, this function returns NULL.
To learn more about the optional arguments in this function and how to use them, see Aggregate function calls.
Return Data Type
FLOAT64
VARIANCE
VARIANCE(
[ DISTINCT ]
expression
[ HAVING { MAX | MIN } expression2 ]
)
Description
An alias of VAR_SAMP.