DDL Statements
The index and partitioning expression recommendations produced by the Teradata Index Wizard are a set of SQL DDL requests drawn from the following list:
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This statement … |
Permits you to test the effects of … |
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ALTER TABLE … MODIFY PRIMARY INDEX |
adding a row‑partitioned primary index to a base table without actually doing so. The types of PARTITION BY clauses that are supported in Validation mode are limited to those types that are recommended by the Index Wizard: those defined over a single column using a RANGE_N function. Any subsequent queries whose plans are captured in the session are optimized and costed as if the table were row‑partitioned according to the specified PARTITION BY clause. Because this request is submitted in Index Validation mode, the usual restriction that the table being altered must be empty does not apply because you are not changing the definition of the actual data table. See “ALTER TABLE” in SQL Data Definition Language. |
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CREATE INDEX |
adding a secondary index without actually doing so. See “CREATE INDEX” in SQL Data Definition Language. |
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DROP INDEX |
dropping a secondary index without actually doing so. If you submit a DROP INDEX request, then the corresponding index definition is considered dropped until you reset the Index Validation mode to NOT ON FOR SESSION. See “DROP INDEX” in SQL Data Definition Language. |
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CREATE JOIN INDEX |
adding a join index without actually doing so. See “CREATE JOIN INDEX” in SQL Data Definition Language. |