Efficient Roll-Up and Drill-Down Analysis in Relational Databases

Large collections of data, e.g. archives of POS (point-of-sale) in the consumer packaged goods as well as in prescription drugs, are typically iteratively classified by a hierarchy [6] on the members of some attributes. Most of the fortune 500 businesses have found ways to consolidate the data archive into a relational database manager. One of the most common steps in "investigative data exploration" is the navigation of the hierarchy to glean valuable insights about the state of the business. The exploration answers "what if" questions, e.g., whatif the retailing of toys were discontinued in all stores and an investment made for building a retail organization for personal computers. To answer such questions, we are required to take the data associated with the lowest level of the hierarchy (e.g., sales) of individual items and sum it up to the ancestor at the highest level of the hierarchy, an operation referred to as roll-up. A human analyst, with the aid of tools, usually narrows do..