The Internet community has recently been focused on peer-to-peer systems like Napster, Gnutella, and Freenet. The grand vision --- a decentralized community of machines pooling their resources to benefit everyone --- is compelling for many reasons: scalability, robustness, lack of need for administration, and even anonymity and resistance to censorship.

The problem of answering queries using views is to nd ecient methods of answering a query using a set of previously materialized views over the database, rather than accessing the database relations. The problem has recently received signicant attention because of its relevance to a wide variety of data management problems, such as query optimization, the maintenance of physical data independence, data integration and data warehousing. This article surveys the theoretical issues concerning the problem of answering queries using views. 1

The explosion of the amount of information available in digital form has made search a hot research topic for the Information Management Community. While most of the research on search is focused on the WWW, individual computer users have developed their own vast collections of data on their desktops, and these collections are in critical need for good search tools. We describe the Semex System that offers users a flexible platform for personal information management. Semex has two main goals. The first goal is to enable browsing personal information by semantically meaningful associations. The challenge it to automatically create such associations between data items on one’s desktop, and to create enough of them so Semex becomes an indispensable tool. Our second goal is to leverage the personal information space we created to increase users ’ productivity. As our first target, Semex leverages the personal information to enable lightweight information integration tasks that are discouragingly difficult to perform with today’s tools.

The Internet community has recently been focused on peer-to-peer systems like Napster, Gnutella, and Freenet, The grand vision — a decentralized community of machines pooling their resources to benefit everyone — is compelling for many reasons: scalability, robustness, lack of need for administration, and even anonymity and resistance to censorship. Esisting peer-to-peer (P2P) systems have focused on specific application domains (e.g. music files) or on providing file-system-like capabilities; these systems ignore the semantics of data, An important question for the database communityis how data management can be applied to P2P, and what we can learn from and contribute to the P2P area. We address these questions, identify a number of potential research ideas in the overlap between data management and P2P systems, present some preliminary fundamental results, and describe our initial work in constructing a P2P data management system.

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Sensor networks are being widely deployed for measurement, detection and surveillance applications. In these new applications, users issue long-running queries over a combination of stored data and sensor data. Most existing applications rely on a centralized system for collecting sensor data.

As databases become more pervasive through the biological sciences, various data quality concerns are emerging. Biological databases tend to develop data quality issues regarding data legacy, data uniformity and data duplication. Due to the nature of this data, each of these problems is non-trivial and can cause many problems for the database. For biological data to be corrected and standardized, methods and frameworks must be developed to handle both structural and traditional data. The BIO-AJAX framework has been developed for solving these problems through both data cleaning and data integration. This framework exploits declarative data cleaning and exploratory data mining to help improve biological data quality. Within the framework, the problems and difficulties for cleaning biological data are discussed, specifically concerning phylogenetic data. Subsequently, it is demonstrated how BIO-AJAX can be used to improve the quality of the data in phylogeny. Moreover, within the cleaning architecture, data integration plays a key role in improving data quality. Data integration, due to the distributed and heterogeneous nature of the data sets becomes an enabling technology for improving data quality. From these concepts, two tools have been built, BIO-AJAX for TreeBASE and BIO-AJAX for Lineage Paths. Each system approaches the data quality problem using the conceptual BIO-AJAX framework while implementing different methods working within the framework to improve the data quality.