Example: Statistics Are Not Copied When Set Or Aggregation Operators Are Specified in the Query - Teradata Vantage

Vantage does not copy statistics if set operators or aggregation operations are specified in the query as these examples demonstrate.

Example1

In this example, Vantage does not copy statistics because of the aggregating GROUP BY clause in the subquery.

    CREATE TABLE t3 (c1, c2) AS (SELECT MAX(x), y
                                 FROM test   
                                 GROUP BY 2) 
    WITH DATA AND STATISTICS;

Example2

In this example, Vantage does not copy statistics because of the aggregating GROUP BY clause in the subquery:

    CREATE TABLE t3 (c1, c2) AS (SELECT COUNT(x), y 
                                 FROM test 
                                 GROUP BY 2) 
    WITH DATA AND STATISTICS;

Example3

In this example, Vantage does not copy statistics because of the aggregating GROUP BY and HAVING clauses in the subquery.

    CREATE TABLE t3(a, b, c) AS (SELECT x1, MIN(y1), AVG(a1)
                                 FROM test1 
                                 GROUP BY x1 
                                 HAVING AVG(y1) > 40) 
    WITH DATA AND STATISTICS;