Paper 2
Update Management in Decision Support SystemsAuthors: Haitang Feng, Nicolas Lumineau, Mohand-Sad Hacid, and Richard Domps |
AbstractForecasting is the process of making statements about events whose actual outcomes have not yet been observed. It is used for decades in dierent elds like climate, crime, health, business… Although the purpose of dierent forecasting systems is not the same, in general, they help decision-makers to make appropriate plans for future likely events. As the nature of forecasting methods and measures are often quanti- tative, these predictive analytics systems usually use a data warehouse to store data and OLAP tools to visualize query/simulation results. A specic feature of forecasting systems regarding predictions analysis is backward propagation of updates, which is the computation of the impact, on raw data, of modications performed on summaries. In data warehouses, some methods propagate updates over hierarchies when modications are performed on data sources. However, so far, very few works have been devoted to update propagation from summaries to raw data. This paper proposes an algorithm called PAM (Propagation of Aggregate-based Modication), to eciently propagate modications performed on summaries to raw data, and then to other summaries. Ex- periments have been conducted on an operational application |