This chapter describes Teradata SQL DML statements used to collect or analyze data demographics and statistics. The collected data is used to populate user-defined QCD tables with data used by various Teradata utilities to analyze query workloads as part of the ongoing process to reengineer the database design process. For example, the Teradata Index Wizard determines optimal secondary and single-table join index sets to support the query workloads you ask it to analyze.
It also describes some SQL DIAGNOSTIC statements used to support the Teradata Index Wizard, Optimizer costing, and the cost-based and sample-based components of the Target Level Emulation facility used to emulate a Teradata production environment on a test system. Once the test environment has been configured and enabled with the appropriate production system statistical and demographic data, you can perform various workload analyses to determine optimal sets of secondary and single-table join indexes to support those workloads in the production environment.
Query capture databases (QCD) are described in detail in SQL Request and Transaction Processing .
The Teradata Index Wizard is described in the following documents:
- Teradata Index Wizard User Guide
- SQL Request and Transaction Processing
SQL Request and Transaction Processing describes Target Level Emulation.
For information about Teradata Database data control language (DCL) statements, see SQL Data Control Language .
HELP and SHOW statements are described in SQL Data Definition Language .
Database query logging is described in Database Administration .
For brief statement descriptions, see SQL Quick Reference .