Sampling Example 2: Conditional Sampling, Variable Sample Rates - Teradata Vantage

This example applies sampling rates 20%, 30%, and 40% to categories fair, very good, and excellent, respectively, and rounds the number sampled to the nearest integer.

Input

• score_category, as in Sampling Example 1: Unconditional Sampling, Single Sample Rate

SQL Call

The arguments StratumColumn and Strata always appear together.

SELECT * FROM Sampling (
  ON score_category PARTITION BY ANY
  USING
  SampleFraction (0.2, 0.3, 0.4)
  StratumColumn ('stratum')
  Strata ('fair', 'very good', 'excellent')
  Seed (2)
) AS dt ORDER BY stratum, id, score;

Output