Results 1 - 10 of 19,647

The Lorel Query Language for Semistructured Data

by Serge Abiteboul, Dallan Quass, Jason Mchugh, Jennifer Widom, Janet Wiener - International Journal on Digital Libraries , 1997
"... We present the Lorel language, designed for querying semistructured data. Semistructured data is becoming more and more prevalent, e.g., in structured documents such as HTML and when performing simple integration of data from multiple sources. Traditional data models and query languages are inapprop ..."
Abstract - Cited by 731 (29 self) - Add to MetaCart
are inappropriate, since semistructured data often is irregular, some data is missing, similar concepts are represented using different types, heterogeneous sets are present, or object structure is not fully known. Lorel is a user-friendly language in the SQL/OQL style for querying such data effectively. For wide

Querying object-oriented databases

by Michael Kifer, Won Kim, Yehoshua Sagiv - ACM SIGMOD INTERNATIONAL CONFERENCE ON MANAGEMENT OF DATA , 1992
"... We present a novel language for querying object-oriented databases. The language is built around the idea of extended path expressions that substantially generalize [ZAN83], and on an adaptation of the first-order formalization of object-oriented languages from [KW89, KLW90, KW92]. The language inco ..."
Abstract - Cited by 492 (6 self) - Add to MetaCart
We present a novel language for querying object-oriented databases. The language is built around the idea of extended path expressions that substantially generalize [ZAN83], and on an adaptation of the first-order formalization of object-oriented languages from [KW89, KLW90, KW92]. The language

VisualSEEk: a fully automated content-based image query system

by John R. Smith, Shih-fu Chang , 1996
"... We describe a highly functional prototype system for searching by visual features in an image database. The VisualSEEk system is novel in that the user forms the queries by diagramming spatial arrangements of color regions. The system finds the images that contain the most similar arrangements of ..."
Abstract - Cited by 762 (31 self) - Add to MetaCart
We describe a highly functional prototype system for searching by visual features in an image database. The VisualSEEk system is novel in that the user forms the queries by diagramming spatial arrangements of color regions. The system finds the images that contain the most similar arrangements

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
. We provide performance results based on our implementation of DataGuides in the Lore DBMS for semistructured data. We also describe the use of DataGuides in Lore, both in the user interface to enable structure browsing and query formulation, and as a means of guiding the query processor

NiagaraCQ: A Scalable Continuous Query System for Internet Databases

by Jianjun Chen, David J. Dewitt, Feng Tian, Yuan Wang - In SIGMOD , 2000
"... Continuous queries are persistent queries that allow users to receive new results when they become available. While continuous query systems can transform a passive web into an active environment, they need to be able to support millions of queries due to the scale of the Internet. No existing syste ..."
Abstract - Cited by 584 (9 self) - Add to MetaCart
Continuous queries are persistent queries that allow users to receive new results when they become available. While continuous query systems can transform a passive web into an active environment, they need to be able to support millions of queries due to the scale of the Internet. No existing

The Cougar Approach to In-Network Query Processing in Sensor Networks

by Yong Yao, Johannes Gehrke - SIGMOD Record , 2002
"... The widespread distribution and availability of smallscale sensors, actuators, and embedded processors is transforming the physical world into a computing platform. One such example is a sensor network consisting of a large number of sensor nodes that combine physical sensing capabilities such as te ..."
Abstract - Cited by 498 (1 self) - Add to MetaCart
the data is aggregated and stored for offline querying and analysis. This approach has two major drawbacks. First, the user cannot change the behavior of the system on the fly. Second, conservation of battery power is a major design factor, but a central system cannot make use of in-network programming

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
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

Kademlia: A Peer-to-peer Information System Based on the XOR Metric

by Petar Maymounkov, David Mazières , 2002
"... We describe a peer-to-peer system which has provable consistency and performance in a fault-prone environment. Our system routes queries and locates nodes using a novel XOR-based metric topology that simplifies the algorithm and facilitates our proof. The topology has the property that every message ..."
Abstract - Cited by 834 (3 self) - Add to MetaCart
message exchanged conveys or reinforces useful contact information. The system exploits this information to send parallel, asynchronous query messages that tolerate node failures without imposing timeout delays on users.

Improving retrieval performance by relevance feedback

by Gerard Salton, Chris Buckley - Journal of the American Society for Information Science , 1990
"... Relevance feedback is an automatic process, introduced over 20 years ago, designed to produce improved query formulations following an initial retrieval operation. The principal relevance feedback methods described over the years are examined briefly, and evaluation data are included to demonstrate ..."
Abstract - Cited by 756 (6 self) - Add to MetaCart
the effectiveness of the various methods. Prescriptions are given for conducting text re-trieval operations iteratively using relevance feedback. Introduction to Relevance Feedback It is well known that the original query formulation process is not transparent to most information system users. In particular

Access path selection in a relational database management system

by P. Griffiths Selinger, M. M. Astrahan, D. D. Chamberlin, It. A. Lorie, T. G. Price , 1979
"... ABSTRACT: In a high level query and data manipulation language such as SQL, requests are stated non-procedurally, without reference to access paths. This paper describes how System R chooses access paths for both simple (single relation) and complex queries (such as joins), given a user specificatio ..."
Abstract - Cited by 587 (1 self) - Add to MetaCart
ABSTRACT: In a high level query and data manipulation language such as SQL, requests are stated non-procedurally, without reference to access paths. This paper describes how System R chooses access paths for both simple (single relation) and complex queries (such as joins), given a user
Results 1 - 10 of 19,647