In general, OLAP data is aggregated and obtained from a relational database source. As a result, there may be occasions where you want to see the relational data associated with the multi-dimensional data.
For example, assume that you create an OLAP analysis to show your company’s sales aggregated to Country, State, and City levels. Assume further that the sales data for each store within a city is stored in a transactional, relational database. In this case, you could drill down in the OLAPQuery section to sales data for USA, then California, and then San Francisco. To see the data for the stores in San Francisco, however, you would need to drill through to a relational database.
Drilling through from a multi-dimensional database to a relational database involves: