Results 1 - 10 of 946

Federated database systems for managing distributed, heterogeneous, and autonomous databases

by Amit P. Sheth, James A. Larson - ACM Computing Surveys , 1990
"... A federated database system (FDBS) is a collection of cooperating database systems that are autonomous and possibly heterogeneous. In this paper, we define a reference architecture for distributed database management systems from system and schema viewpoints and show how various FDBS architectures c ..."
Abstract - Cited by 1218 (34 self) - Add to MetaCart
A federated database system (FDBS) is a collection of cooperating database systems that are autonomous and possibly heterogeneous. In this paper, we define a reference architecture for distributed database management systems from system and schema viewpoints and show how various FDBS architectures

Tinydb: An acquisitional query processing system for sensor networks

by Samuel R. Madden, Michael J. Franklin, Joseph M. Hellerstein, Wei Hong - ACM Trans. Database Syst , 2005
"... We discuss the design of an acquisitional query processor for data collection in sensor networks. Acquisitional issues are those that pertain to where, when, and how often data is physically acquired (sampled) and delivered to query processing operators. By focusing on the locations and costs of acq ..."
Abstract - Cited by 626 (8 self) - Add to MetaCart
, and execution. We evaluate these issues in the context of TinyDB, a distributed query processor for smart sensor devices, and show how acquisitional techniques can provide significant reductions in power consumption on our sensor devices. Categories and Subject Descriptors: H.2.3 [Database Management

The state of the art in distributed query processing

by Donald Kossmann - ACM Computing Surveys , 2000
"... Distributed data processing is fast becoming a reality. Businesses want to have it for many reasons, and they often must have it in order to stay competitive. While much of the infrastructure for distributed data processing is already in place (e.g., modern network technology), there are a number of ..."
Abstract - Cited by 320 (3 self) - Add to MetaCart
of issues which still make distributed data processing a complex undertaking: (1) distributed systems can become very large involving thousands of heterogeneous sites including PCs and mainframe server machines � (2) the state of a distributed system changes rapidly because the load of sites varies over

Query optimization in database systems

by Matthias Jarke, Jürgen Koch - ACM Computing Surveys , 1984
"... Efficient methods of processing unanticipated queries are a crucial prerequisite for the success of generalized database management systems. A wide variety of approaches to improve the performance of query evaluation algorithms have been proposed: logic-based and semantic transformations, fast imple ..."
Abstract - Cited by 231 (0 self) - Add to MetaCart
Efficient methods of processing unanticipated queries are a crucial prerequisite for the success of generalized database management systems. A wide variety of approaches to improve the performance of query evaluation algorithms have been proposed: logic-based and semantic transformations, fast

KMS: A distributed Hypermedia system for managing Knowledge in Organizations

by Robert Akscyn, Donald Mccracken, Elise Yoder - Communications of the ACM , 1988
"... KMS is a commercial hypermedia system developed by Knowledge Systems for networks of heterogeneous workstations. It is designed to support organization-wide collaboration for a broad range of applications, such as electronic publishing, software engineering, project management, computer-aided design ..."
Abstract - Cited by 198 (2 self) - Add to MetaCart
KMS is a commercial hypermedia system developed by Knowledge Systems for networks of heterogeneous workstations. It is designed to support organization-wide collaboration for a broad range of applications, such as electronic publishing, software engineering, project management, computer

Issues and approaches of database integration

by Christine Parent, Stefano Spaccapietra - Communications of the ACM , 1998
"... In many large companies the widespread usage of computers has led a number of different application-specific databases to be installed. As company structures evolve, boundaries between departments move, creating new business units. Their new applications will use existing data from various data stor ..."
Abstract - Cited by 67 (0 self) - Add to MetaCart
of scalable data integration and site autonomy requirements [9]. Federated systems are very popular today. However, before they become marketable, many issues remain to be solved. Design issues focus on either human-centered aspects (cooperative work, including autonomy issues and negotiation procedures

An Adaptive Data Replication Algorithm

by Ouri Wolfson, Sushil Jajodia, Yixiu Huang - ACM Transactions on Database Systems , 1997
"... This paper addresses the performance of distributed database systems. Specifically, we present an algorithm for dynamic replication of an object in distributed systems. The algorithm is adaptive in the sense that it changes the replication scheme of the object (i.e. the set of processors at which th ..."
Abstract - Cited by 185 (0 self) - Add to MetaCart
and recovery mechanisms of a distributed database management system. The performance of the algorithm is analyzed theoretically and experimentally. On the way we provide a lower bound on the performance of any dynamic replication algorithm.

Self-determination and persistence in a real-life setting: Toward a motivational model of high school dropout.

by Robert J Vallerand , Michelle S Fbrtier , Frederic Guay - Journal of Personality and Social Psychology, , 1997
"... The purpose of this study was to propose and test a motivational model of high school dropout. The model posits that teachers, parents, and the school administration's behaviors toward students influence students' perceptions of competence and autonomy. The less autonomy supportive the so ..."
Abstract - Cited by 183 (19 self) - Add to MetaCart
in the .50 and .60 range may be regarded as problematic by some researchers. We feel that there is no need for concern on this issue, however, because internal consistency that is based on the alpha coefficient may not be an adequate reliability estimate for a scale made up of a small number of items. Indeed

Autonomy Requirements in Heterogeneous Distributed Database Systems

by Panos Chrysanthis, Krithi Ramamritham - in Proceedings of the 6th International Conference on Management of Data , 1994
"... In the context of multidatabase systems and heterogeneous distributed database systems, it has been observed that autonomy of the component databases has to be violated in order to maintain traditional database and transaction properties. However, very little work exists that systematically analyzes ..."
Abstract - Cited by 6 (3 self) - Add to MetaCart
analyzes (a) the semantics of autonomy and (b) the implications of autonomy vis a vis correctness specifications and database protocols. Hence, this paper is aimed at characterizing the different types of autonomy by focusing on transaction management and showing the relationships between autonomy

A Case for Economy Grid Architecture for Service Oriented Grid Computing

by Rajkumar Buyya , David Abramson , Jonathan Giddy , 2001
"... Computational Grids are a promising platform for executing large-scale resource intensive applications. However, resource management and scheduling in the Grid environment is a complex undertaking as resources are (geographically) distributed, heterogeneous in nature, owned by different individuals ..."
Abstract - Cited by 149 (33 self) - Add to MetaCart
control, scalability, transparency, resource brokering, and "computational economy". A number of Grid systems (such as Globus and Legion) have addressed many of these issues with exception of a computational economy. We argue that a computational economy is required in order to create a real
Results 1 - 10 of 946