Returns the sample variance for the data points in value_expression.
To invoke the time series version of this function, use the GROUP BY TIME clause. For more information, see Teradata Vantage™ - Time Series Tables and Operations, B035-1208.
The variance of a sample is a measure of dispersion from the mean of that sample. It is the square of the sample standard deviation.
The computation is more conservative than that for the population standard deviation to minimize the effect of outliers on the computed value.
When the sample used for the computation has fewer than two non-null data points, VAR_SAMP returns NULL.
Division by zero results in NULL rather than an error.