Results 1 - 10 of 9,246

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

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

Logical foundations of object-oriented and frame-based languages

by Michael Kifer, Georg Lausen, James Wu - JOURNAL OF THE ACM , 1995
"... We propose a novel formalism, called Frame Logic (abbr., F-logic), that accounts in a clean and declarative fashion for most of the structural aspects of object-oriented and frame-based languages. These features include object identity, complex objects, inheritance, polymorphic types, query methods, ..."
Abstract - Cited by 876 (65 self) - Add to MetaCart
We propose a novel formalism, called Frame Logic (abbr., F-logic), that accounts in a clean and declarative fashion for most of the structural aspects of object-oriented and frame-based languages. These features include object identity, complex objects, inheritance, polymorphic types, query methods

Tractable reasoning and efficient query answering in description logics: The DL-Lite family

by Diego Calvanese, G. De Giacomo, Domenico Lembo, Maurizio Lenzerini, Riccardo Rosati - J. OF AUTOMATED REASONING , 2007
"... We propose a new family of Description Logics (DLs), called DL-Lite, specifically tailored to capture basic ontology languages, while keeping low complexity of reasoning. Reasoning here means not only computing subsumption between concepts, and checking satisfiability of the whole knowledge base, b ..."
Abstract - Cited by 497 (123 self) - Add to MetaCart
to the logics of the DL-Lite family make query answering at least NLogSpace in data complexity, thus ruling out the possibility of using on-the-shelf relational technology for query processing, we can conclude that the logics of the DL-Lite family are the maximal DLs supporting efficient query answering over

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

A Query Language and Optimization Techniques for Unstructured Data

by Peter Buneman, Susan Davidson, Gerd Hillebrand, Dan Suciu , 1996
"... A new kind of data model has recently emerged in which the database is not constrained by a conventional schema. Systems like ACeDB, which has become very popular with biologists, and the recent Tsimmis proposal for data integration organize data in tree-like structures whose components can be used ..."
Abstract - Cited by 407 (35 self) - Add to MetaCart
equally well to represent sets and tuples. Such structures allow great flexibility in data representation What query language is appropriate for such structures? Here we propose a simple language UnQL for querying data organized as a rooted, edge-labeled graph. In this model, relational data may

Models and issues in data stream systems

by Brian Babcock, Shivnath Babu, Mayur Datar, Rajeev Motwani, Jennifer Widom - IN PODS , 2002
"... In this overview paper we motivate the need for and research issues arising from a new model of data processing. In this model, data does not take the form of persistent relations, but rather arrives in multiple, continuous, rapid, time-varying data streams. In addition to reviewing past work releva ..."
Abstract - Cited by 786 (19 self) - Add to MetaCart
relevant to data stream systems and current projects in the area, the paper explores topics in stream query languages, new requirements and challenges in query processing, and algorithmic issues.

Notes On Formalizing Context

by John McCarthy , 1993
"... These notes discuss formalizing contexts as first class objects. The basic relation is ist(c; p). It asserts that the proposition p is true in the context c. The most important formulas relate the propositions true in different contexts. Introducing contexts as formal objects will permit axiomatizat ..."
Abstract - Cited by 417 (9 self) - Add to MetaCart
These notes discuss formalizing contexts as first class objects. The basic relation is ist(c; p). It asserts that the proposition p is true in the context c. The most important formulas relate the propositions true in different contexts. Introducing contexts as formal objects will permit

Featherweight Java: A Minimal Core Calculus for Java and GJ

by Atsushi Igarashi, Benjamin C. Pierce, Philip Wadler - ACM Transactions on Programming Languages and Systems , 1999
"... Several recent studies have introduced lightweight versions of Java: reduced languages in which complex features like threads and reflection are dropped to enable rigorous arguments about key properties such as type safety. We carry this process a step further, omitting almost all features of the fu ..."
Abstract - Cited by 659 (23 self) - Add to MetaCart
of the full language (including interfaces and even assignment) to obtain a small calculus, Featherweight Java, for which rigorous proofs are not only possible but easy. Featherweight Java bears a similar relation to Java as the lambda-calculus does to languages such as ML and Haskell. It offers a similar

A translation approach to portable ontology specifications

by Thomas R. Gruber - KNOWLEDGE ACQUISITION , 1993
"... To support the sharing and reuse of formally represented knowledge among AI systems, it is useful to define the common vocabulary in which shared knowledge is represented. A specification of a representational vocabulary for a shared domain of discourse — definitions of classes, relations, functions ..."
Abstract - Cited by 3365 (9 self) - Add to MetaCart
To support the sharing and reuse of formally represented knowledge among AI systems, it is useful to define the common vocabulary in which shared knowledge is represented. A specification of a representational vocabulary for a shared domain of discourse — definitions of classes, relations
Results 1 - 10 of 9,246