15.10 - Example: Collecting Statistics on a Constant Expression - 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

This example collects statistics on constant expressions, that is, an expression that does not refer to columns by name.

     COLLECT STATISTICS USING SYSTEM SAMPLE
     COLUMN 100,
     COLUMN CURRENT_DATE+10
     ON orders;

In this example, the Optimizer eliminates the constant expressions 100 and CURRENT_DATE+10 from the COLLECT STATISTICS request.

Because the rewritten expressions do not refer to columns, the Optimizer rewrites the request to use the SUMMARY option. The Optimizer also removes the USING SYSTEM SAMPLE option from the final request.

     COLLECT SUMMARY STATISTICS 
     ON orders;