Oscar Romero

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Nowadays, it is widely accepted that the data warehouse design task should be largely automated. Furthermore, the data warehouse conceptual schema must be structured according to the multidimensional model and as a consequence, the most common way to automatically look for subjects and dimensions of analysis is by discovering functional dependencies (as(More)
This paper describes the convergence of some of the most influential technologies in the last few years, namely data warehousing (DW), on-line analytical processing (OLAP), and the Semantic Web (SW). OLAP is used by enterprises to derive important business-critical knowledge from data inside the company. However, the most interesting OLAP queries can no(More)
Although multidimensionality has been widely accepted as the best solution to conceptual modeling, there is not such agreement about the set of operators to handle multidimensional data. This paper presents a comparative of the existing multidimensional algebras trying to find a common backbone, as well as it discusses about the necessity of a reference(More)
Available online 15 July 2010 The data warehouse design task needs to consider both the end-user requirements and the organization data sources. For this reason, the data warehouse design has been traditionally considered a reengineering process, guided by requirements, from the data sources. Most current design methods available demand highly-expressive(More)
At the early stages of a data warehouse design project, the main objective is to collect the business requirements and needs, and translate them into an appropriate conceptual, multidimensional design. Typically, this task is performed manually, through a series of interviews involving two different parties: the business analysts and technical designers.(More)
In the last years, the problems of using generic storage techniques for very specific applications has been detected and outlined. Thus, some alternatives to relational DBMSs (e.g., BigTable) are blooming. On the other hand, cloud computing is already a reality that helps to save money by eliminating the hardware as well as software fixed costs and just pay(More)
In this paper we present a method to validate user multidimensional requirements expressed in terms of SQL queries. Furthermore, our approach automatically generates and proposes the set of multidimensional schemas satisfying the user requirements, from the organizational operational schemas. If no multidimensional schema is generated for a query, we can(More)
Article history: Received 7 October 2008 Received in revised form 9 March 2010 Accepted 11 March 2010 Available online 27 March 2010 It iswidely accepted that the conceptual schemaof a datawarehousemust be structuredaccording to themultidimensionalmodel. Moreover, it has been suggested that the ideal scenario for deriving the multidimensional conceptual(More)