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…

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)…

The term Federated Databases refers to the data integration of distributed, autonomous and heterogeneous databases. However, a federation can also include information systems, not only databases. At integrating data, several issues must be addressed. Here, we focus on the problem…

The studies of Relational Data Base Management Systems and Databases constitute nowadays a main tren of investigation in large businesses and universities of the entire world. The creation of a data base engine keeps being a challenge since there are…

The main objective of this paper centers on reviewing the evolution of Decision Support System´s (DSS) architectures, particularly as they apply to natural resources. Today it is difficult to conceive the existence of a rural planning automated system that doesn't…

Vertical partitioning, in which attributes of a relation are
assigned to partitions, is aimed at improving database
performance. We extend previous research that is based on
a single relation to multi-relation database environment,
by including referential integrity constraints, access time

This paper is an attempt to define how a
specific data structure might be used to
store, in a persistent manner, temporal
information during a computer simulation.
In particular, it considers the sort of
temporal information generated during a
discrete…

Similarity search is a fundamental operation for applications that deal with unstructured data sources. In this paper we propose a new pivot-based method for similarity search, called Sparse Spatial Selection (SSS).
The main characteristic of this method is that it…

The metric spaces model formalizes the similarity search concept in nontraditional databases. The goal is to build an index designed to save distance computations when answering similarity queries later. A large class of algorithms to build the index are based…

Ontology mapping involves the task of finding similarities among overlapping sources by using ontologies. In a Federated System in which distributed, autonomous and heterogeneous information sources must be integrated, ontologies have emerged as tools to solve semantic heterogeneity problems. In…