Introduction to ANSI Valid-Time Tables | ANSI Temporal Table Support | Vantage - Working With 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 Vantage™

Valid time is the time period during which the information in a row is in effect or true for purposes of real-world application. (ANSI calls this period "application time.") Valid-time columns store information such as the time an insurance policy or contract is valid, the length of employment of an employee, or other information that is important to track and manipulate in a time-aware fashion.

Use valid-time tables when the information in table rows is delimited by time, and for which row information should be maintained, tracked, and manipulated in a time-aware fashion.

Valid-time tables are most appropriate when changes to rows occur relatively infrequently. To represent attributes that change very frequently, such as a point of sale table, an event table is preferable to a valid-time table. Temporal semantics do not apply to event tables.

This material covers only the syntax, rules, and other details that apply to ANSI temporal tables. The syntax diagrams presented are extracts of the full diagrams, and focus on the temporal syntax.

Most of the existing rules and options that apply to conventional, nontemporal versions of the SQL statements discussed here also apply to the temporal statements. The nontemporal rules and options are not repeated here. For more information on conventional, nontemporal SQL DDL and DML statements, see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144 and Teradata Vantage™ - SQL Data Manipulation Language, B035-1146 .