Alvaro A. A. Fernandes

Learn More
Distributed query processing (DQP) has been widely used in data intensive applications where data of relevance to users is stored in multiple locations. This paper argues: (i) that DQP can be important in the Grid, as a means of providing high-level, declarative languages for integrating data access and analysis; and (ii) that the Grid provides resource(More)
Service-based approaches (such as Web Services and the Open Grid Services Architecture) have gained considerable attention recently for supporting distributed application development in e-business and e-science. The emergence of a service-oriented view of hardware and software resources raises the question as to how database management systems and(More)
The Grid is an emerging infrastructure that supports the discovery, access and use of distributed computational resources. The emergence of a serviceoriented view of hardware and software resources on the grid raises the question as to how database management systems and technologies can best be deployed or adapted for use in such an environment. We argue(More)
Advances in network technologies and the emergence of Grid computing have both increased the need and provided the infrastructure for computation and data intensive applications to run over collections of heterogeneous and autonomous nodes. In the context of database query processing, existing parallelisation techniques cannot operate well in Grid(More)
OGSA-DQP is a distributed query processor exposed to users as an Open Grid Services Architecture (OGSA)-compliant Grid service. This service supports the compilation and evaluation of queries that combine data obtained from multiple services on the Grid, including Grid Database Services (GDSs) and computational web services. Not only does OGSA-DQP support(More)
Service-based approaches are rising to prominence because of their potential to meet the requirements for distributed application development in e-business and e-science. The emergence of a service-oriented view of hardware and software resources raises the question as to how database management systems and technologies can best be deployed or adapted for(More)
This paper presents an approach to the development of a deductive object-oriented database system, describing the key design decisions and their consequences for implementation. The approach is novel, in that it integrates an object-oriented database system manipulated using an imperative programming language (ROCK) with a logic language for expressing(More)
Workflows are widely used in applications that require coordinated use of computational resources. Workflow definition languages typically abstract over some aspects of the way in which a workflow is to be executed, such as the level of parallelism to be used or the physical resources to be deployed. As a result, a workflow management system has(More)
1. Summary As explicitly stated in the title, this paper presented the advantages of treating user feedback as the first class citizen in the information integration systems. Compared with existing proposals in this area that only deal with specific type of user feedback and often only single user, the information integration systems proposed in this paper(More)
We present a sensor network query processing architecture that covers all the query optimization phases that are required to map a declarative query to executable code. The architecture is founded on the view that a sensor network truly is a distributed computing infrastructure, albeit a very constrained one. As such, we address the problem of how to(More)