What Is Time Variance?
Fon Silvers · Auerbach Publications eBooks · 2011
Time Variance is one of the phrases penned by IT people, for IT people. A data warehouse must represent the events from such an assortment of business units and subject areas. While doing so, the data warehouse must achieve its own balance between the cost of having data and the cost of not having data. The periodicity of transactions is typically short. The periodicity of dimensions is typically long. The goal of a data warehouse is to rationalize the some forms of periodicity into one representation of the enterprise. Time Variance between the price of gasoline and gasoline sales transactions allows the query result set to join them together, even when the result set includes multiple dates. Time Variance allows a data warehouse to join the transactions of the enterprise to the objects and their properties or attributes that were in effect at that moment the transaction occurred.