Temporal tables, as available in Teradata 13.10, are supported in TWM primarily through the support of temporal qualifiers in the Variable Creation analysis (not available in the Teradata Profiler product). Temporal qualifiers may precede the SELECT keyword or follow the table name, derived table, or joined table in the FROM clause of a Select statement. Temporal support is also provided through the support of the Period data types, literals, functions, operators, and built-in functions, as well as the EXPAND ON expert clause in the Variable Creation analysis. Refer also to the Teradata User Documentation beginning with version 13.10 of the database, particularly the volume entitled Temporal Table Support, B035-1182, as well as the volume SQL Data Manipulation Language, B035-1146, which includes more information on the SELECT Statement and the EXPAND ON Clause.
When a temporal or bitemporal table is referenced in a query or used as input to an analysis, the current session Temporal Qualifier is used by default when selecting from that table, and the default session Temporal Qualifier is CURRENT VALIDTIME AND CURRENT TRANSACTIONTIME. This means temporal tables may be analyzed by any TWM analysis using the default session Temporal Qualifier. If a different qualifier is desired, the most straightforward solution is to create a view that incorporates the desired qualifier. For example, the SQL below creates a view incorporating the CURRENT VALIDTIME qualifier.
REPLACE VIEW "twm_source"."twm_temporal_customer_view" AS CURRENT VALIDTIME SELECT * FROM "twm_source"."twm_temporal_customer";
A view such as the one defined above is used to perform any available analysis on the underlying table in the view. Such a view definition can be built using either a Variable Creation analysis, utilizing the selectors available on the analysis parameters panel, or a Free Form SQL analysis.
If it is not practical to create a view with an embedded temporal qualifier, the current session Temporal Qualifier can be changed for some types of analyses by using a statement such as the following, executed before the desired analyses in a Free Form SQL analysis.
set session CURRENT VALIDTIME AND CURRENT TRANSACTIONTIME;
All of the desired analyses to be performed with this temporal qualifier must be executed in the same session, and this is not possible for those types of analysis which make their own connection or connections, including the analytic algorithms and their scoring analyses, the Matrix analysis and the Data Explorer analysis. For other types of analyses, it is still necessary to ensure that the same connection is used for the set session command and each of the analyses that depend on it, which is best guaranteed by executing an entire project that contains the Free Form SQL analysis and dependent analyses.