Conception et manipulation de Bases de donnees Dimensionnelles à contraintes

In decisional systems framework, my thesis focuses on the conception and the querying of multidimensional data.We provide a dimensional model organising data in a constellation of facts (subject of analysis) associated withdimensions (axes of analysis). These dimensions are flexible because each dimension instance can belong to oneor several hierarchies (perspectives of analysis). Moreover, we integrate constraints in the multidimensional modelallowing both the validation of multidimensional structures and the ensure of consistent analyses bydisambiguating null values which can result from the combination of unsuitable hierarchies. To integrate theseconstraints, we define a multidimensional algebra enabling decision-makers to precise instances to analyse.Finally, we provide a conceptual design method of multidimensional data integrating decision-maker needs anddata issued from source schema. To validate our propositions, we provide a CASE tool to help designer to defineconceptual multidimensional schema.