SIGMOD

Internet, Web and distributed computing infrastructures continue to gain in popularity as a means of communication for organizations, groups and individuals alike. In such an environment, characterized by large distributed, autonomous, diverse, and ...

Global information systems have the potential of providing decision makers with timely spatial information about earth systems. This information will come from diverse sources, including field monitoring, remotely sensed imagery, and environmental ...

This paper reports on the principles underlying the semantic and pedagogic interoperability mechanisms built in the European Knowledge Pool System, developed by the European research project ARIADNE. This system, which is the central feature of ARIADNE, ...

Semantic interoperability is a growing challenge in the United States Department of Defense (DoD). In this paper, we describe the basis of an infrastructure for the reconciliation of relevant, but semantically heterogeneous attribute values. Three types ...

Providing concept level access to video data requires, video management systems tailored to the domain of the data. Effective indexing and retrieval for high-level access mandates the use of domain knowledge. This paper proposes an approach based on the ...

Rapid growth in the volume of documents, their diversity, and terminological variations render federated digital libraries increasingly difficult to manage. Suitable abstraction mechanisms are required to construct meaningful and scalable document ...

Providing an integrated access to multiple heterogeneous sources is a challenging issue in global information systems for cooperation and interoperability. In this context, two fundamental problems arise. First, how to determine if the sources contain ...

The Brazilian Symposium on Database Systems (SBBD) is a traditional conference in Brazil, and is sponsored by the Brazilian Computer Society. SBBD's technical program contemplates the following activities: presentation of peer reviewed full technical ...

Given the complexity of many queries over a Data Warehouse (DW), it is interesting to precompute and store in the DW the answer sets of some demanding operations, so called materialized views. In this paper, we present an algorithm, including its ...

A point data retrieval algorithm for the HG-tree is introduced which improves the number of nodes accessed. The HG-tree is a multidimensional indexing tree designed for point data and it is a simple modification from the Hilbert R-tree for indexing ...

The OASIS Prototype is under development at Dublin City University in Ireland. We describe a multi-database architecture which uses the ODMG model as a canonical model and describe an extention for construction of virtual schemas within the ...

Visual information, especially videos, plays an increasing role in our society for both work and entertainment as more sources become available to the user. Set-top boxes are poised to give home users access to videos that come not only from TV channels ...

For several years now, you've been hearing and reading about an emerging standard that everybody has been calling SQL3. Intended as a major enhancement of the current second generation SQL standard, commonly called SQL-92 because of the year it was ...