Modifying Rows in ANSI Valid-Time Tables - 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„¢

When modifications are made to rows in temporal tables, Vantage provides automatic handling of the valid-time periods as needed to maintain the information in a time-aware fashion.

DELETE and UPDATE modifications to valid-time tables can use the FOR PORTION OF qualifier to place time bounds on the effectiveness of the modifications. The time during which a change is effective is called the period of applicability (PA) of the modification. Vantage selects the rows that are affected based on the relationship between the PA of the change and the valid-time period of the row, also called the period of validity (PV) of the row because that period defines when the information is considered to be in effect.

The relationship between the PA of a modification and PV of each row determines which rows qualify for the modification. It also determines when the change is effective and whether new rows will be automatically created in the table to account for data that changes during the valid-time period.

The mechanism of new rows being automatically generated by Vantage for modifications to temporal tables is described in more detail in Modifying Temporal Tables.