DESCRIPTION

This function computes a value for each record returned by the query predicate, or from the specified column of a base table, and returns the population standard deviation of those values.

Expression expr must be the name of a column in a LiveView table, where that column's data type is int, long, double, or timestamp. If the field's type is an int, double, or long, it returns a double. If the field's type is a timestamp, it returns an interval timestamp. For timestamp values, the input field should contain all interval timestamps or all absolute timestamps, but not both.

This function calculates its return value based on the biased or n method, and is usually used when the incoming data represents the entire population of data. Use stdev, which calculates its return value using the unbiased or n-1 method, when the incoming data represents a random sample of data.

SEE ALSO

This LiveView aggregate function is based on the stdevp aggregate function in the StreamBase expression language.