The applicability period (or period of applicability) for a modification (generally an insertion, deletion, or update) is the time period that modification is to be applied. Generally the modification is a sequenced modification and the period applies to valid time. This period should be distinguished from lifespan.
The applicability period is specified within a modification statement. In constrast, the lifespan is an aspect of a stored fact.
This illustration uses the TSQL2 language, which has an explicit VALID clause to specify the applicability period within an INSERT, DELETE, or UPDATE statement.
INSERT INTO EMPLOYEE
VALUES (‘Ben’, ‘Book’)
VALID PERIOD ‘[15 Feb 2007, 15 Mar 2007]’