José Samos

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"On-Line Analytical Processing" tools are used to extract information from the "Data Warehouse" in order to help in the decision making process. These tools are based on multidimensional concepts, i.e. facts and dimensions. In this paper we study the meaning of facts, and the dependencies in multidimensional data. This study is used to find relationships(More)
The words On-Line Analytical Processing bring together a set of tools, that use multidimensional modeling in the management o f information to improve the decision making process. Lately, a l o t o f w ork has been devoted to modeling the multidimensional space. The aim of this paper is twofold. On one hand, it compiles and classiies some of that work, with(More)
In the last years, lots of work have been devoted to multidimensional modeling, star shape schemas and OLAP operations. However, "drill-across" has not captured as much attention as other operations. This operation allows to change the subject of analysis keeping the same analysis space we were using to analyze another subject. It is assumed that this can(More)
OLAP tools divide concepts based on whether they are used as analysis dimensions, or are the fact subject of analysis, which gives rise to star shape schemas. Operations are always provided to navigate inside such star schemas. However, the navigation among different stars is usually overlooked. This paper studies different kinds of Object-Oriented(More)
In recent years, data warehouses have reached a prominent position in the database field, especially in the database industry. There are many issues in common between data warehouses and other database fields such as federated databases; in our opinion this fact has not been explored in its entirety. In this paper, an integrated database architecture in(More)
OLAP defines a set of data warehousing query tools characterized by providing a multidimen-sional view of data. Information can be shown at different aggregation levels (often called granular-ities) for each dimension. In this paper, we try to outline the benefits of understanding the relationships between those aggregation levels as Part-Whole(More)
Jos e S a m o s (c) F elix Saltor (a) Abstract This paper is devoted to Secure Data Warehousing architecture and its data schemas. We relate a feder-ated databases architecture to Data Warehouse schemas, which allows us to provide better understanding to the characteristics of every schema, as we l l a s t h e w ay they should be deened.(More)