COVAR_SAMP()

Sample covariance

Result type

DOUBLE PRECISION

Syntax

COVAR_SAMP ( <expr1>, <expr2> )

Table 1. `COVAR_SAMP` Function Parameters
Parameter	Description
exprN	Numeric expression.It may contain a table column, a constant, a variable, an expression, a non-aggregate function or a UDF.Aggregate functions are not allowed as expressions.

The function COVAR_SAMP returns the sample covariance for a pair of numerical expressions.

The function COVAR_SAMP(<expr1>, <expr2>) is equivalent to

(SUM(<expr1> * <expr2>) - SUM(<expr1>) * SUM(<expr2>) / COUNT(*)) / (COUNT(*) - 1)

If the group or window is empty, contains only 1 row, or contains only NULL values, the result will be NULL.

select
  covar_samp(alength, aheight) AS c_covar_samp
from measure