Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | ACM Digital Library |
|---|---|
| Author | Fuxman, Ariel Kolaitis, Phokion G. Miller, Renée J. Tan, Wang-Chiew |
| Abstract | In this paper, we introduce and study a framework, calledpeer data exchange, for sharing and exchanging data betweenpeers. This framework is a special case of a full-fledged peer datamanagement system and a generalization of data exchange between asource schema and a target schema. The motivation behind peer dataexchange is to model authority relationships between peers, where asource peer may contribute data to a target peer, specified usingsource-to-target constraints, and a target peer may usetarget-to-source constraints to restrict the data it is willing toreceive, but cannot modify the data of the source peer.A fundamental algorithmic problem in this framework is that ofdeciding the existence of a solution: given a source instance and atarget instance for a fixed peer data exchange setting, can thetarget instance be augmented in such a way that the source instanceand the augmented target instance satisfy all constraints of thesetting? We investigate the computational complexity of the problemfor peer data exchange settings in which the constraints are givenby tuple generating dependencies. We show that this problem isalways in NP, and that it can be NP-complete even for "acyclic"peer data exchange settings. We also show that the data complexityof the certain answers of target conjunctive queries is in coNP,and that it can be coNP-complete even for "acyclic" peer dataexchange settings.After this, we explore the boundary between tractability andintractability for the problem of deciding the existence of asolution. To this effect, we identify broad syntactic conditions onthe constraints between the peers under which testing for solutionsis solvable in polynomial time. These syntactic conditions includethe important special case of peer data exchange in which thesource-to-target constraints are arbitrary tuple generatingdependencies, but the target-to-source constraints arelocal-as-view dependencies. Finally, we show that the syntacticconditions we identified are tight, in the sense that minimalrelaxations of them lead to intractability. |
| Starting Page | 160 |
| Ending Page | 171 |
| Page Count | 12 |
| File Format | |
| ISBN | 1595930620 |
| DOI | 10.1145/1065167.1065188 |
| Language | English |
| Publisher | Association for Computing Machinery (ACM) |
| Publisher Date | 2005-06-13 |
| Publisher Place | New York |
| Access Restriction | Subscribed |
| Content Type | Text |
| Resource Type | Article |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|