The SQL Server VAR returns the Variance of the total number of records present in the specified column. For example, the following query will calculate the variance of total records present in the [Yearly Income] column from the Customers table.

What is variance in database?

VARIANCE returns the variance of expr . You can use it as an aggregate or analytic function. Oracle Database calculates the variance of expr as follows: 0 if the number of rows in expr = 1. VAR_SAMP if the number of rows in expr > 1.

Is variance () an aggregate function?

It is an aggregate function, and so can be used with the GROUP BY clause. From MariaDB 10.2. 2, VARIANCE() can be used as a window function.