UPDATE Statement (ANSI System-Time Table Form) | Teradata Vantage - UPDATE (ANSI System-Time Table Form) - Analytics Database - Teradata Vantage

ANSI Temporal Table Support

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
VMware
Product
Analytics Database
Teradata Vantage
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-10-30
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lifecycle
latest
Product Category
Teradata Vantageā„¢

Modifies column values in existing rows of system-time tables.

Syntax

There is no special additional temporal syntax for the UPDATE statement when used on a system-time table. The syntax is identical to that used for nontemporal tables. That syntax is described fully in Teradata Vantageā„¢ - SQL Data Manipulation Language, B035-1146.

Usage Notes

Although the syntax for a UPDATE statement is identical for system-time and non-temporal tables, the effects are different. When you change a row in a nontemporal table, the original information in the row no longer exists. The situation can be thought of as if the original row had been deleted and replaced with a new row.

System-time tables make this implicit situation explicit, by literally deleting the original row from the table and inserting a new row into the table to reflect the modified information. Because rows are never physically deleted from system-time tables, the original row is closed in system time, and remains inactive in the table as a snapshot of how the table existed before the change.

Updates so not affect closed rows in system-time tables.

The SET clause cannot include the beginning or ending column components of the SYSTEM_TIME derived period column.