On-line analytical processing

On-line analytical processing (OLAP) describes an approach to decision support, which aims to extract knowledge from a data warehouse, or more specifically, from data marts. Its main idea is providing navigation through data to non-expert users, so that they are able to interactively generate ad hoc queries without the intervention of IT professionals. This name was introduced in contrast to on-line transactional processing (OLTP), so that it reflected the different requirements and characteristics between these classes of uses. The concept falls in the area of business intelligence.Peer ReviewedPostprint (author's final draft

Update Management in Decision Support Systems

International audienceForecasting is the process of making statements about eventswhose actual outcomes have not yet been observed. It is used for decadesin different fields like climate, crime, health, business... Although thepurpose of different forecasting systems is not the same, in general, theyhelp decision-makers to make appropriate plans for future likely events.As the nature of forecasting methods and measures are often quantitative, these predictive analytics systems usually use a data warehouseto store data and OLAP tools to visualize query/simulation results. Aspecific feature of forecasting systems regarding predictions analysis isbackward propagation of updates, which is the computation of theimpact, on raw data, of modifications performed on summaries.In data warehouses, some methods propagate updates over hierarchieswhen modifications are performed on data sources. However, so far, veryfew works have been devoted to update propagation from summaries toraw data. This paper proposes an algorithm called PAM (Propagationof Aggregate-based Modification), to efficiently propagate modificationsperformed on summaries to raw data, and then to other summaries. Ex-periments have been conducted on an operational application