DIAGNOSTIC “Validate Index” - Teradata Database

Enables or disables the index and partition validation mode for the session and validates the indexes and partitioning expressions proposed by the Teradata Index Wizard utility.

Alternatively, you can use the statement to evaluate user‑specified indexes and partitioning expressions.

where:

Syntax element …	Specifies that index validation is …
NOT ON	Disabled for the session.
ON	Enabled for the session. When validation mode is turned ON, you can issue any of the following statements to simulate the existence (or nonexistence) of indexes and partitioning expressions for validation without actually creating or altering them. ALTER TABLE … MODIFY PRIMARY INDEX COLLECT STATISTICS (QCD Form) CREATE INDEX CREATE JOIN INDEX DROP INDEX DROP JOIN INDEX DROP STATISTICS (QCD Form) INSERT EXPLAIN
FOR SESSION	Set at the session scope level. No other diagnostic scope levels are valid.

DIAGNOSTIC “validate index” is a Teradata extension to the ANSI SQL:2011 specification.

None.

Normally invoked using the Teradata Index Wizard utility.

If you are performing index analysis on a non‑production system, you must have Target Level Emulation enabled to use the DIAGNOSTIC “validate index” statement. For more information about Target Level Emulation, see SQL Request and Transaction Processing.

DIAGNOSTIC “Validate Index” enables you to capture query plans and then to examine whether or not the cost of the resulting plan is improved by the availability of simulated indexes or partitioning expressions.