15.10 - Example: Statistics Are Not Copied When Set Or Aggregation Operators Are Specified In The Query - Teradata Database

Teradata Database SQL Data Definition Language Syntax and Examples

prodname
Teradata Database
vrm_release
15.10
created_date
December 2015
category
Programming Reference
featnum
B035-1144-151K

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

Example1

In this example, Teradata Database 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, Teradata Database 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, Teradata Database 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;