Results 1 - 10 of 16,830

Search and replication in unstructured peer-to-peer networks

by Qin Lv, Pei Cao, Edith Cohen, Kai Li, Scott Shenker , 2002
"... Abstract Decentralized and unstructured peer-to-peer networks such as Gnutella are attractive for certain applicationsbecause they require no centralized directories and no precise control over network topologies and data placement. However, the flooding-based query algorithm used in Gnutella does n ..."
Abstract - Cited by 692 (6 self) - Add to MetaCart
Abstract Decentralized and unstructured peer-to-peer networks such as Gnutella are attractive for certain applicationsbecause they require no centralized directories and no precise control over network topologies and data placement. However, the flooding-based query algorithm used in Gnutella does

Nearest neighbor queries.

by Nick Roussopoulos , Stephen Kelley , Fr Ed , Eric Vincent - ACM SIGMOD Record, , 1995
"... Abstract A frequently encountered type of query in Geographic Information Systems is to nd the k nearest neighbor objects to a given point in space. Processing such queries requires substantially di erent search algorithms than those for location or range queries. In this paper we present a n e cie ..."
Abstract - Cited by 592 (1 self) - Add to MetaCart
Abstract A frequently encountered type of query in Geographic Information Systems is to nd the k nearest neighbor objects to a given point in space. Processing such queries requires substantially di erent search algorithms than those for location or range queries. In this paper we present a n e

Query evaluation techniques for large databases

by Goetz Graefe - ACM COMPUTING SURVEYS , 1993
"... Database management systems will continue to manage large data volumes. Thus, efficient algorithms for accessing and manipulating large sets and sequences will be required to provide acceptable performance. The advent of object-oriented and extensible database systems will not solve this problem. On ..."
Abstract - Cited by 767 (11 self) - Add to MetaCart
-relational database systems, including iterative execution of complex query evaluation plans, the duality of sort- and hash-based set matching algorithms, types of parallel query execution and their implementation, and special operators for emerging database application domains.

Answering Queries Using Views: A Survey

by Alon Y. Halevy , 2000
"... The problem of answering queries using views is to find efficient methods of answering a query using a set of previously defined materialized views over the database, rather than accessing the database relations. The problem has recently received significant attention because of its relevance to a w ..."
Abstract - Cited by 562 (32 self) - Add to MetaCart
surveys the state of the art on the problem of answering queries using views, and synthesizes the disparate works into a coherent framework. We describe the different applications of the problem, the algorithms proposed to solve it and the relevant theoretical results.

DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases

by Roy Goldman, Jennifer Widom , 1997
"... In semistructured databases there is no schema fixed in advance. To provide the benefits of a schema in such environments, we introduce DataGuides: concise and accurate structural summaries of semistructured databases. DataGuides serve as dynamic schemas, generated from the database; they are ..."
Abstract - Cited by 572 (13 self) - Add to MetaCart
; they are useful for browsing database structure, formulating queries, storing information such as statistics and sample values, and enabling query optimization. This paper presents the theoretical foundations of DataGuides along with an algorithm for their creation and an overview of incremental maintenance

Query by Committee

by H. S. Seung, M. Opper, H. Sompolinsky , 1992
"... We propose an algorithm called query by committee, in which a committee of students is trained on the same data set. The next query is chosen according to the principle of maximal disagreement. The algorithm is studied for two toy models: the high-low game and perceptron learning of another perceptr ..."
Abstract - Cited by 432 (3 self) - Add to MetaCart
We propose an algorithm called query by committee, in which a committee of students is trained on the same data set. The next query is chosen according to the principle of maximal disagreement. The algorithm is studied for two toy models: the high-low game and perceptron learning of another

An Efficient Boosting Algorithm for Combining Preferences

by Raj Dharmarajan Iyer , Jr. , 1999
"... The problem of combining preferences arises in several applications, such as combining the results of different search engines. This work describes an efficient algorithm for combining multiple preferences. We first give a formal framework for the problem. We then describe and analyze a new boosting ..."
Abstract - Cited by 727 (18 self) - Add to MetaCart
The problem of combining preferences arises in several applications, such as combining the results of different search engines. This work describes an efficient algorithm for combining multiple preferences. We first give a formal framework for the problem. We then describe and analyze a new

Relational Databases for Querying XML Documents: Limitations and Opportunities

by Jayavel Shanmugasundaram, Kristin Tufte, Gang He, Chun Zhang, David DeWitt, Jeffrey Naughton , 1999
"... XML is fast emerging as the dominant standard for representing data in the World Wide Web. Sophisticated query engines that allow users to effectively tap the data stored in XML documents will be crucial to exploiting the full power of XML. While there has been a great deal of activity recently prop ..."
Abstract - Cited by 478 (9 self) - Add to MetaCart
proposing new semistructured data models and query languages for this purpose, this paper explores the more conservative approach of using traditional relational database engines for processing XML documents conforming to Document Type Descriptors (DTDs). To this end, we have developed algorithms

An algorithm for finding best matches in logarithmic expected time

by Jerome H. Friedman, Jon Louis Bentley, Raphael Ari Finkel - ACM Transactions on Mathematical Software , 1977
"... An algorithm and data structure are presented for searching a file containing N records, each described by k real valued keys, for the m closest matches or nearest neighbors to a given query record. The computation required to organize the file is proportional to kNlogN. The expected number of recor ..."
Abstract - Cited by 764 (2 self) - Add to MetaCart
An algorithm and data structure are presented for searching a file containing N records, each described by k real valued keys, for the m closest matches or nearest neighbors to a given query record. The computation required to organize the file is proportional to kNlogN. The expected number

Efficient Query Evaluation on Probabilistic Databases

by Nilesh Dalvi, Dan Suciu , 2004
"... We describe a system that supports arbitrarily complex SQL queries with ”uncertain” predicates. The query semantics is based on a probabilistic model and the results are ranked, much like in Information Retrieval. Our main focus is efficient query evaluation, a problem that has not received attentio ..."
Abstract - Cited by 456 (47 self) - Add to MetaCart
We describe a system that supports arbitrarily complex SQL queries with ”uncertain” predicates. The query semantics is based on a probabilistic model and the results are ranked, much like in Information Retrieval. Our main focus is efficient query evaluation, a problem that has not received
Results 1 - 10 of 16,830