Sometimes, you just don’t have a data warehouse from which to get data for your data mart, so you have to source the data from applications yourself.
In many (probably most) of these situations, you create a quick-strike data mart — in effect, a miniature data warehouse but built to meet the demands of a set of users who need the data content now. You follow the same meth- odology and complete the same processes of data extraction, transformation, quality assurance, and loading as described in Chapter 3. The difference
is that you use this methodology on a smaller scale than you do with a full-blown data warehouse.