VARIANCE is one of the vital Analytic functions of Oracle. It is used to get the variance of a set of numbers. The VARIANCE function is supported in the various versions of the Oracle/PLSQL, including, Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i and Oracle 8i.
VARIANCE ( expression )
expression: It is used to specify the numerical expression to be used for calculation.
select VARIANCE (marks) from students;
Here, the variance will be returned for the field called ‘marks’ of the ‘students’ table.