Example

Teradata Vantageā„¢ Data Types and Literals

brand
Software
Teradata Vantage
prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
category
Programming Reference
featnum
B035-1143-162K

Assume that the current date is DATE '2008-05-14' at time zone displacement, INTERVAL '09:00' HOUR TO MINUTE, but the current date is DATE '2008-05-13' at time zone, INTERVAL -'08:00' HOUR TO MINUTE. The following SELECT statement returns the result: TIMESTAMP '2008-05-14 08:30:00'.

SET TIME ZONE INTERVAL '09:00' HOUR TO MINUTE;
SELECT CAST(TIME '08:30:00' AS TIMESTAMP(0) AT -8);

The current session time zone displacement, INTERVAL '09:00' HOUR TO MINUTE, is used to determine the UTC value '23:30:00' of the literal. For the CAST, the source expression value '23:30:00' at UTC is adjusted to the target time zone displacement, INTERVAL -'08:00' HOUR TO MINUTE, to yield '15:30:00'.

A timestamp is formed from the current date '2008-05-13' at time zone displacement, INTERVAL -'08:00' HOUR TO MINUTE, and the time portion of the source expression value '15:30:00' obtained after the above adjustment. Then this resulting timestamp '2008-05-13 15:30:00' at time zone displacement, INTERVAL -'08:00' HOUR TO MINUTE, is adjusted to UTC so that the CAST result is '2008-05-13 23:30:00' at UTC.

The result value of the CAST at UTC is adjusted to the current session time zone displacement, INTERVAL '09:00' HOUR TO MINUTE, so the result of the SELECT statement is: TIMESTAMP '2008-05-14 08:30:00'.