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…

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…

In situ hybridization (ISH) method allows to reveal specific genes expression, identify specific cell types and detect areas or tissues, displaying differential gene expression. This work describes a standardized procedure of digital image processing that allows detailed analyses of ISH…

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…

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 Semantic Web attempts to reach a state in the future where everything on the Web will no longer be only machine-readable, but also machine-understandable. An ontology is an explicit specification of a conceptualization. A conceptualization is an abstract, simplified…

The concept of “approximate” searching has applications in a vast number of fields. Some examples are non-traditional databases (e. g. storing images, fingerprints or audio clips, where the concept of exact search is of no use and we search instead…