Modélisation et manipulation de données historisées et archivées dans un entrepôt orienté objet

National audienceThis paper deals with temporal and archive object-oriented data warehouse modelling and querying. In a first step, we define a data model describing warehouses as central repositories of complex and temporal data extracted from one information source. The model is based on the concepts of warehouse object and environment. A warehouse object is composed of one current state, several past states (modelling value changes) and several archive states (summarising some value changes). An environment defines temporal parts in a warehouse schema according to a relevant granularity (attribute, class or graph). In a second step, we provide a query algebra dedicated to data warehouses. This algebra, which is based on common object algebras, integrates temporal operators and operators for querying object states. An other important contribution concerns dedicated operators allowing users to transform warehouse objects in temporal series as well as operators facilitating analytical treatments

Personnalisation de bases de données multidimensionnelles

National audienceThis paper deals with decision support systems resting on multidimensional modelling of data. Moreover, we intend to offer a set of concepts and mechanisms for personalized multidimensional database specifications. This personalization consists in associating weights to different components of a multidimensional schema. Personalization specifications are specified through the use of a language based on the principle of Event Condition Action. This personalisation determines multidimensional data display as well as their analyses (with the use of drilling or rotating operations)

Modèles et outils pour la conception et la manipulation de systèmes d'aide à la décision

Nos travaux se situent dans le cadre des Systèmes d'Aide à la Décision (SAD). Au début de nos travaux, nous étions en présence de solutions d'ordre technique pour l'alimentation des SAD (vues matérialisées) ainsi que de quelques solutions parcellaires pour la modélisation et les manipulations multidimensionnelles. Durant ces dernières années, notre objectif a été d'offrir une solution globale pour la conception et la manipulation de SAD. Dans un premier temps, nous avons identifié deux espaces de stockage pour les données décisionnelles : un Entrepôt de Données (ED) et des Magasins de Données (MD). Un ED centralise et historise les données issues des sources de production et chaque MD présente les données à un décideur pour faciliter ses prises de décisions. Pour les ED, notre objectif a été d'apporter des solutions pour la modélisation de l'évolution des données décisionnelles (extension de modèle objet) et pour l'intégration de données textuelles sans en fixer le schéma à priori. Pour les MD, nous avons proposé un modèle multidimensionnel de base avec différentes extensions répondant aux besoins des décideurs. Ces extensions permettent de prendre en compte la gestion d'indicateurs et de données textuelles, l'évolution temporelle (versions), la cohérence des données et de ses analyses (contraintes sémantiques), l'intégration et la capitalisation de l'expertise des décideurs (annotations) ainsi que la personnalisation des schémas multidimensionnels (poids). Ces travaux ont été complétés par la proposition d'une démarche de conception qui présente l'avantage de prendre en compte les besoins des décideurs et les sources de données. Cette démarche permet de modéliser aussi bien l'aspect statique (données décisionnelles) que l'aspect dynamique (processus d'alimentation du SAD).D'un point de vue manipulation des données, nous avons proposé une algèbre complétée d'un langage graphique orienté décideur et d'un langage déclaratif. Nos propositions ont été validées par la participation à différents projets ainsi que le co-encadrement de 5 thèses de doctorat et le suivi de travaux de plusieurs Master Recherche

Modélisation et extraction de données pour un entrepôt objet

National audienceThis paper describes an object-oriented model for designing complex and time-variant data warehouse data. The main contribution is the warehouse class concept, which extends the class concept by temporal and archive filters as well as a mapping function. Filters allow the keeping of relevant data changes whereas the mapping function defines the warehouse class schema from a global data source schema. The approach take into account static properties as well as dynamic properties. The behaviour extraction is based on the use-matrix concept

Algèbre OLAP et langage graphique

National audienceThis article deals with OLAP systems based on multidimensional model. The conceptual model we provide, represents data through a constellation (multi-facts) composed of several multi-hierarchy dimensions. In this model, data are displayed through multidimensional tables. We define a query algebra handling these tables. This user oriented algebra is composed of a closure core of OLAP operators as soon as advanced operators dedicated to complex analysis. Finally, we specify a graphical OLAP language based on this algebra. This language facilitates analyses of decision makers

Modélisation de la Structure Complexe des Faits et des Mesures

National audienceDecision support system (DSS) goal is to help decision-makers. They are modeled mainly in a multdimiensional way, that means activity analysis subjects, called facts, with their measures are represented as the center of a star with dimensions and their parameters around. Several models have been devoted to DSS representation, but they handle only relationships between dimensions and their parameters. Recently, some relationships between facts have been analyzed. Relationships between measures indicate correlations through a given activity because they represent properties of this activity. However, there is no work on these relationships. Therefore, we model facts and measures such as relationships between these concepts. We define a UML-based model because it allows a representation related and adapted to DSS terminology and it is well-known by a large amount of designers

Analysis Framework for Reduced Data Warehouse

International audienceOur aim is to define a framework supporting analysis in MDW with reductions. Firstly, we describe a modeling solution for reduced MDW. A schema of reduced MDW is composed of states. Each state is defined as a star schema composed of one fact and its related dimensions valid for a certain period of time. Secondly, we present a multi-state analysis framework. Extensions of classical drilldown and rollup operators are defined to support multi-states analyses. Finally we present a prototype of our framework aiming to prove the feasibility of concept. By implementing our extended operators, the prototype automatically generates appropriate SQL queries over metadata and reduced data

Méthode de Développement des Systèmes d'Information Décisionnels : Roue de Deming

National audienceID6, a company specialized in decisional support systems (DSS), requested a development method for such systems. This method must achieve a fast development of reliable DSS according to user requirements in a context oriented reuse. None of the existing DSS-specific methods has become a standard. Moreover, they do not favor reuse of knowledge. In order to take advantages of our convention with I-D6, we decided to define a method according to Deming Wheel. For the four iterations of our method definition, we use the Deming cycle. We present in this paper the process of our method definition according to Deming Wheel