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 di erent elds like climate, crime, health, business… Although the purpose of di erent 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 speci c feature of forecasting systems regarding predictions analysis is backward propagation of updates, which is the computation of the impact, on raw data, of modi cations performed on summaries. In data warehouses, some methods propagate updates over hierarchies when modi cations 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 Modi cation), to eciently propagate modi cations performed on summaries to raw data, and then to other summaries. Ex- periments have been conducted on an operational application |