Results 1 - 10 of 254

Overview of Datalog Extensions with Tuples and Sets

by Mengchi Liu , 1998
"... Datalog (with negation) is the most powerful query language for relational database with a well-defined declarative semantics based on the work in logic programming. However, Datalog only allows inexpressive flat structures and cannot directly support complex values such as nested tuples and sets co ..."
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common in novel database applications. For these reasons, Datalog has been extended in the past several years to incorporate tuple and set constructors. In this paper, we examine four different Datalog extensions: LDL, COL, Hilog and Relationlog. 1 Introduction Databases and logic programming are two

Equivalence, Query-Reachability, and Satisfiability in Datalog Extensions (Extended Abstract)

by Alon Y. Levy, Inderpal Singh Mumick, Yehoshua Sagiv, Oded Shmueli - In Proceedings of the ACM Symposium on Principles of Database Systems , 1993
"... Alon Y. Levy Stanford University levy@cs.stanford.edu Inderpal Singh Mumick AT&T Bell Laboratories mumick@research.att.com Yehoshua Sagiv y Hebrew University sagiv@cs.huji.ac.il Oded Shmueli z Technion---Israel Institute of Technology oshmu@cs.technion.ac.il Abstract We consider the ..."
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the problems of equivalence, satisfiability and query-reachability for datalog programs with negation and dense-order constraints. These problems are important for optimizing datalog programs. We show that both queryreachability and satisfiability are decidable for programs with stratified negation provided

SociaLite: Datalog Extensions for Efficient Social Network Analysis

by Jiwon Seo, Stephen Guo, Monica S. Lam
"... Abstract — With the rise of social networks, large-scale graph analysis becomes increasingly important. Because SQL lacks the expressiveness and performance needed for graph algorithms, lower-level, general-purpose languages are often used instead. For greater ease of use and efficiency, we propose ..."
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SociaLite, a high-level graph query language based on Datalog. As a logic programming language, Datalog allows many graph algorithms to be expressed succinctly. However, its performance has not been competitive when compared to low-level languages. With SociaLite, users can provide high-level hints

Complexity and Expressive Power of Logic Programming

by Evgeny Dantsin, Thomas Eiter, Georg Gottlob, Andrei Voronkov , 1997
"... This paper surveys various complexity results on different forms of logic programming. The main focus is on decidable forms of logic programming, in particular, propositional logic programming and datalog, but we also mention general logic programming with function symbols. Next to classical results ..."
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This paper surveys various complexity results on different forms of logic programming. The main focus is on decidable forms of logic programming, in particular, propositional logic programming and datalog, but we also mention general logic programming with function symbols. Next to classical

Memoing Evaluation for Constraint Extensions of Datalog

by David Toman, Raghu Ramakrishnan, Peter Stuckey - Constraints , 1997
"... . This paper proposes an efficient method for evaluation of deductive queries over constraint databases. The method is based on a combination of the top-down resolution with memoing and the closed form bottom-up evaluation. In this way the top-down evaluation is guaranteed to terminate for all queri ..."
Abstract - Cited by 25 (2 self) - Add to MetaCart
constraints during the computation. In addition, the top-down evaluation potentially allows the use of compilation techniques, developed for compilers of logic programming languages, which can make the query evaluation very efficient. Keywords: Datalog, constraint class, top-down evaluation, memoing

An Extension of Datalog for Graph Queries An Extension of Datalog for Graph Queries ⋆ Ex

by Mirjana Mazuran, Edoardo Serra, Carlo Zaniolo, Mirjana Mazuran, Edoardo Serra, Carlo Zaniolo
"... Abstract. Supporting aggregates in recursive logic rules is a crucial long-standing problem for Datalog. To solve this problem, we propose F S Datalog that supports queries and reasoning on the number of distinct occurrences satisfying given goals, or conjunction of goals, in rules. By using a gener ..."
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generalized notion of multiplicity called frequency, we show that graph queries can be easily expressed in Datalog F S. This simple extension preserves all the desirable semantic and computational properties of logic-based languages, while significantly extending their application range to support efficiently

Hypothetical Datalog: Complexity and Expressibility

by Anthony Bonner - Theoretical Computer Science , 1988
"... We present an extension of Horn-clause logic which can hypothetically add and delete tuples from a database. Such logics have been discussed in the literature, but their complexities and expressibilities have remained an open question. This paper examines two such logics in the function-free, predic ..."
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We present an extension of Horn-clause logic which can hypothetically add and delete tuples from a database. Such logics have been discussed in the literature, but their complexities and expressibilities have remained an open question. This paper examines two such logics in the function

From Fuzzy- to Bipolar- Datalog

by Ágnes Achs
"... Abstract. In this work we present several possible extensions of fuzzy Datalog. At first the concept of fuzzy Datalog will be summarized, then its extension for intuitionistic- and interval-valued fuzzy logic is given and the concept of bipolar fuzzy Datalog is introduced. ..."
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Abstract. In this work we present several possible extensions of fuzzy Datalog. At first the concept of fuzzy Datalog will be summarized, then its extension for intuitionistic- and interval-valued fuzzy logic is given and the concept of bipolar fuzzy Datalog is introduced.

Fundamental properties of deterministic and nondeterministic extensions of Datalog

by Serge Abiteboul, Eric Simon - Theoretical Computer Science , 1991
"... Fundamental properties of deterministic and nondeterministic extensions of Datalog from [AV88] are studied. The extensions involve the use of negative literals both in bodies and heads of rules. Negative literals in heads are interpreted as deletions. A deterministic semantics is obtained by firi ..."
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Fundamental properties of deterministic and nondeterministic extensions of Datalog from [AV88] are studied. The extensions involve the use of negative literals both in bodies and heads of rules. Negative literals in heads are interpreted as deletions. A deterministic semantics is obtained

dcs: An Implementation of DATALOG with Constraints

by Deborah East, Miroslaw Truszczynski , 2000
"... Answer-set programming (ASP) has emerged recently as a viable programming paradigm. We describe here an ASP system, DATALOG with constraints or DC, based on non-monotonic logic. Informally, DC theories consist of propositional clauses (constraints) and of Horn rules. The semantics is a simple a ..."
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Answer-set programming (ASP) has emerged recently as a viable programming paradigm. We describe here an ASP system, DATALOG with constraints or DC, based on non-monotonic logic. Informally, DC theories consist of propositional clauses (constraints) and of Horn rules. The semantics is a simple
Results 1 - 10 of 254