Ricardo Jorge Santos

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The purpose of a data warehouse is to aid decision making. As the real-time enterprise evolves, synchronism between transactional data and data warehouses is redefined. To cope with real-time requirements, the data warehouses must be able to enable continuous data integration, in order to deal with the most recent business data. Traditional data warehouses(More)
Technological evolution has redefined many business models. Many decision makers are now required to act near real-time, instead of periodically, given the latest transactional information. Decision-making occurs much more frequently and considers the latest business data. Since data warehouses (DWs) are the core of business intelligence, decision support(More)
Decision support for 24/7 enterprises requires 24/7 available Data Warehouses (DWs). In this context, web-based connections to DWs are used by business management applications demanding continuous availability. Given that DWs store highly sensitive business data, a web-based connection provides a door for outside attackers and thus, creates a main security(More)
Data Warehouses (DWs) are the core of enterprise sensitive data, which makes protecting confidentiality in DWs a critical task. Published research and best practice guides state that encryption is the best way to achieve this and maintain high performance. However, although encryption algorithms strongly fulfill their security purpose, we demonstrate that(More)
—Data Warehouses (DWs) are the enterprise's most valuable assets in what concerns critical business information, making them an appealing target for malicious inside and outside attackers. Given the volume of data and the nature of DW queries, most of the existing data security solutions for databases are inefficient, consuming too many resources and(More)
Data Warehouses (DWs) are the enterprise's most valuable asset in what concerns critical business information, making them an appealing target for attackers. Packaged database encryption solutions are considered the best solution to protect sensitive data. However, given the volume of data typically processed by DW queries, the existing encryption solutions(More)
—Data Warehouses (DWs) store the golden nuggets of the business, which makes them an appealing target. To ensure data privacy, encryption solutions have been used and proven efficient in their security purpose. However, they introduce massive storage space and performance overheads, making them unfeasible for DWs. demonstrate its overall effectiveness.(More)
Databases often support enterprise business and store its secrets. This means that securing them from data damage and information leakage is critical. In order to deal with intrusions against database systems, Database Intrusion Detection Systems (DIDS) are frequently used. This paper presents a survey on the main database intrusion detection techniques(More)
The sudden fall of blood pressure (hypotension) is a common complication in medical care. In critical care patients, hypotension (HT) may cause serious heart, endocrine or neurological disorders, inducing severe or even lethal events. Moreover, recent studies report an increase of mortality in HT prone hemodialysis patients in need of critical care. If HT(More)