16.20 - Producing the Final Group Result - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL External Routine Programming

Product
Advanced SQL Engine
Teradata Database
Release Number
16.20
Release Date
April 2020
Content Type
Programming Reference
Publication ID
B035-1147-162K
Language
English (United States)

During the AGR_FINAL aggregation phase, a UDF produces the final result for the group. The method must set the result value to the final value.

In the standard deviation example, the method can use the following code to calculate the final value:

double term2 = s1.x_sum/s1.count;
double variance = s1.x_sq/s1.count - term2*term2;

The following statement sets the result value to the final value of the standard deviation:

return new Double(Math.sqrt(variance));