16.20 - Modifying Row Partitioning Defined With an Updatable DATE, CURRENT_DATE, or CURRENT_TIMESTAMP - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantage™ SQL Data Definition Language Detailed Topics

Product
Teradata Database
Teradata Vantage NewSQL Engine
Release Number
16.20
Release Date
March 2019
Content Type
Programming Reference
Publication ID
B035-1184-162K
Language
English (United States)

Teradata Database provides a special version of the ALTER TABLE statement for modifying the row partitioning of a table (or WHERE clause of a join index definition) defined with an updatable DATE, updatable CURRENT_DATE, or updatable CURRENT_TIMESTAMP built-in function called ALTER TABLE TO CURRENT (see ALTER TABLE TO CURRENT).

ALTER TABLE TO CURRENT is designed specifically to reconcile the values of these functions when they are specified in a partitioning expression of a table or join index or in the WHERE clause of a join index.

The rules for ALTER TABLE TO CURRENT requests are identical for row partitioning and column partitioning; however, there can be a negative performance impact if the table or join index has column partitioning in addition to row partitioning because it is often costly to move a row from one row partition to another.

See the table in Comparing ALTER TABLE TO CURRENT and ALTER TABLE … REVALIDATE for a comparison of the capabilities of ALTER TABLE … REVALIDATE PRIMARY INDEX requests with the ALTER TABLE TO CURRENT statement.