An essential part of many organisations is the ability to provide the users and decision makers with reports on key data based on large amounts data, and these reports should be delivered in a timely manner to stay relevant.

To get the desired performance the programs generating these reports are often written in a non-intuitive fashion. For instance, by keeping data in a denormalized form. We have investigated an alternative approach, namely to write the programs as they are operating on the full amount of data and then use automatic incrementalization for achieving acceptable performance.