17.00 - Example: Collecting Statistics on a Constant Expression - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Syntax and Examples

Product
Advanced SQL Engine
Teradata Database
Release Number
17.00
Release Date
September 2020
Content Type
Programming Reference
Publication ID
B035-1144-170K
Language
English (United States)

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;