A data warehouse efficiently processes a given set of queries by utilizing the multiple materialized views. Owing to the constraint on space and maintenance cost, the materialization of all views is unfeasible. One of the critical decisions involved in the…

This paper presents a data structure based on Sparse Spatial Selection (SSS) for similarity searching. An algorithm that tries periodically to adjust pivots to the use of database index is presented. This index is dynamic. In this way, it is…

Nowadays, data intensive applications are in constant demand and there is need of computing environments with better intelligent capabilities than those present in today's Database Management Systems (DBMS). To build such systems we need formalisms that can perform complicate inferences,…

An important problem in Mineralogy, is to accomplish an adequate representation of a great amount of data coming from different geological environments, in order to characterize a particular geologic region in terms of its tectonic setting. With such Databases of…

This paper presents an evolution of a simulation environment where situations in which a DDB should maintain data integrity are modeled and implemented. These situations include failures taking place during transactions, and the focus is mainly on the utilization and…

During recent years, new software engineering paradigms like component-based software engineering and COTS-based development have emerged. Both paradigms are concerned with reuse and customisation of existing components. The use of COTS software has become more and more important in state-of-the-art…

We present partial results of a research project in which we use boolean circuits as a parallel computation model for the expression of queries to relational databases. For that purpose, we use the well-known equivalence between First Order Logic (FO)…

Minimization of query execution time is an important performance objective in distributed databases design. While total time is to be minimized for On Line Transaction Processing (OLTP) type queries, response time has to be minimized in Decision Support type queries.…

E-mail texts are hard to process due to their short length. In this article, the use of a diffuse neural network that is capable of identifying the most relevant terms in a set of e-mails is proposed. The associations between…

The general objective of this thesis is the development of an adaptive technique for extracting knowledge in large databases. Nowadays, technology allows storing huge volumes of information. For this reason, the availability of techniques that allow, as a first stage,…