Filters








1,167 Hits in 4.0 sec

Algebraic optimization of recursive queries

Maurice A.W. Houtsma, Peter M.G. Apers
1992 Data & Knowledge Engineering  
strategies for recursive queries.  ...  In this paper we describe an optimization strategy that rewrites regular (in the context of formal grammars) mutually recursive queries into standard Relational Algebra and transitive closure operations  ...  Acknowledgements We thank the reviewers for their comments, which have greatly improved the quality of the paper.  ... 
doi:10.1016/0169-023x(92)90029-b fatcat:tcydmhdf6zcgri3ty3dmhgmd5i

Transitive closure and the LOGA+-strategy for its efficient evaluation [chapter]

W. Yan, N. Mattos
1989 Lecture Notes in Computer Science  
In this paper, we discuss some important criteria for developing transitive closure algorithms.  ...  One of the key problems when extending relational database query languages to include deductive capabilities, is to provide them with efficient methods for answering recursive queries.  ...  Härder for his helpful comments which contributed to clarify and improve the ideas presented in this paper. Also acknowledged are the careful reading and useful hints of S.  ... 
doi:10.1007/3-540-51251-9_27 fatcat:ygr3dcjsabd4lnlkk44afbrlay

A Materialized View for the Same Generation Query in Deductive Databases

Nabil Arman
2012 Computer and Information Science  
Deductive databases take advantage of a special kind of rule recursion called linear recursion to provide inference capabilities to improve the intelligence of the database system.  ...  that provides storage persistence needed for any database system, or by integrating an expert system with a relational database system.  ...  Materialized views were used with transitive closures in deductive databases and proved to be very beneficial in improving the performance of this query (Toroslu, 1998) .  ... 
doi:10.5539/cis.v5n6p1 fatcat:w4gf7kjwzzb4jmgdifcjur5gpe

Integrating Complex Objects and Recursion [chapter]

Harald Schöning
1990 Deductive and Object-Oriented Databases  
Since these structures may be recursive, transitive closure computations are supported in a natural way.  ...  The molecule-atom data model (MAD model) supports the management of complex objects in databases. It allows for the dynamic definition of complex object structures at query time.  ...  Some algorithms proposed for transitive closure computations work on all data, i.e. compute the transitive closure of a whole relation.  ... 
doi:10.1016/b978-0-444-88433-6.50038-1 fatcat:lzmcq52zlzbejcg77ybiqr6bje

Optimization of Linear Recursive Queries in SQL

Carlos Ordonez
2010 IEEE Transactions on Knowledge and Data Engineering  
Query optimization is studied with two important graph problems: computing the transitive closure of a graph and getting the power matrix of its adjacency matrix.  ...  Recursion is a fundamental computation mechanism which has been incorporated into SQL. This work focuses on the optimization of linear recursive queries in SQL.  ...  Direct Algorithm to Evaluate a Recursive Query Direct algorithms were adapted to evaluate a transitive closure query in a database system [2] .  ... 
doi:10.1109/tkde.2009.83 fatcat:qopingnlorfdhlnlygjrbcj6ly

Architectural Considerations for Extending a Relational DBMS with Deductive Capabilities [chapter]

Michael Dobrovnik, Roland T. Mittermeir
1992 Shifting Paradigms in Software Engineering  
Knowledge processing capabilities of SQL were enhanced by extending the language by recursive views.  ...  This paper describes the development rationale and the architecture of a prototypical expert-database system.  ...  Integration of Generalized Transitive Closure into SQL General transitive closure is a special form of a linear recursive deduction rule.  ... 
doi:10.1007/978-3-7091-9258-0_9 fatcat:7ozxks32xzbvfeg6f4qevladji

A Variant of Earley Deduction With Partial Evaluation [article]

Heike Stephan, Stefan Brass
2014 arXiv   pre-print
In certain cases, the new method is more efficient than SLDMagic and the standard Magic Set method since it can process several deduction steps as one.  ...  We present an algorithm for query evaluation given a logic program consisting of function-free Datalog rules.  ...  Whereas in earlier times deductive database research was concentrated only on recursive query evaluation, now new applications, e. g. for the semantic web, are in the focus.  ... 
arXiv:1405.5645v1 fatcat:xgycljiak5cyvayjx5htamrgga

Maintenance of Recursive Views [chapter]

Suzanne W. Dietrich
2017 Encyclopedia of Database Systems  
Consider a change in the underlying graph for the transitive closure example.  ...  The power of recursive views was first introduced in the Datalog query language, which is a declarative logic programming language established as the database query language for deductive databases in  ...  (a,f) (b,f) Repeat until no change: No new tuples for Δ -(r1) and Δ -(r22) Δ -(r21): δ -(reach(S, D)) :-δ -(reach(S, I)), edge(I, D).  ... 
doi:10.1007/978-1-4899-7993-3_842-2 fatcat:fbblwrhi6ndjpdh75nbxr2x4nq

Page 6232 of Mathematical Reviews Vol. , Issue 96j [page]

1996 Mathematical Reviews  
databases and queries for which efficient algorithms exist.  ...  It has been shown that query processing in dis- junctive deductive databases grows into CoNP with very simple examples, but few attempts have been made, as is done in this paper, to obtain classes of disjunctive  ... 

Taking the RDF Model Theory Out for a Spin [chapter]

Ora Lassila
2002 Lecture Notes in Computer Science  
In this paper we give some results in our investigation of a practical implementation of the entailment rules, based on the graph-walking query mechanism of the Wilbur RDF toolkit.  ...  Entailment, as defined by RDF's model-theoretical semantics, is a basic requirement for processing RDF, and represents the kind of "semantic interoperability" that RDF-based systems have been anticipated  ...  Acknowledgements The author would like to thank the following individuals for help in the preparation of this article: Mark Adler, Jos de Roo, Pat Hayes, Marcia Lassila, Deborah McGuinness, Esko Nuutila  ... 
doi:10.1007/3-540-48005-6_24 fatcat:datwhsgqlvfivhpn47oklexbey

A survey of deductive database systems

Raghu Ramakrishnan, Jeffrey D. Ullman
1995 The Journal of Logic Programming  
However, a new limit recursion to linear recursion or to restricted forms related to graph searching, such as transitive closure. Negation. Most systems allow negated subgoals in rules.  ...  The area of deductive databases, and in particular, recursive query processing, became very active in 1984 with the initiation of three major projects, two in the U.S.A. and one in Europe. The Nail!  ... 
doi:10.1016/0743-1066(94)00039-9 fatcat:z75hsj363jcwrdic4ymyi7aop4

Operation-oriented query language approach for recursive queries—part 1. Functional definition

Timo Niemi, Kalervo Järvelin
1992 Information Systems  
We also discuss its role in deductive databases, i.e. its integration with processing based on an extensional database.  ...  In our approach recursive processing is needed for constructing transitive relationships among data.  ...  The transitive closure operation is also included in the so-called traversal recursion approach [20] . There are also several algorithms (e.g.  ... 
doi:10.1016/0306-4379(92)90005-8 fatcat:ocquab77arckxpdqw2swhngi5q

On rules and integrity constraints in database systems

T.W. Ling, P.K. Teo
1992 Information and Software Technology  
Deductive rules are more powerful and expressive than relational views. However, support for deductive rules can be problematic with negative information and recursion. formula [17] .  ...  Deductive rules[21] provide a mechanism to derive data which are not explicitly stored in the database. This is the concept of virtual or derived data.  ...  Deductive rules are more powerful and expressive compared to relational views. They can be recursively defined and can compute the transitive closure of a relation.  ... 
doi:10.1016/0950-5849(92)90026-l fatcat:tpqdq552pzfzbeyt3rngjo3lq4

A Natural Logic System for Large Knowledge Bases [chapter]

Troels Andreasen, Henrik Bulskov, Jørgen Fischer Nilsson
2020 Frontiers in Artificial Intelligence and Applications  
The paper proposes and describes realization of deductive querying functionalities using a previously specified natural logic dialect called Natura-Log.  ...  Thereby the inference steps are subjected to computation in bulk for scaling-up to large knowledge bases.  ...  The derived sentences forming a deductive closure are stored so that querying in the natural logic is conducted as a mere retrieval process.  ... 
doi:10.3233/faia200824 fatcat:xs5rq6dhpbavdbejkaiiottvta

A prolog-based framework for search, integration and empirical analysis on software evolution data

Pamela Bhattacharya, Iulian Neamtiu
2011 Proceeding of the 3rd international workshop on Search-driven development: users, infrastructure, tools, and evaluation - SUITE '11  
In this paper, we argue the need for a framework built with recursively enumerable languages, that can answer temporal queries, and supports negation and recursion.  ...  Integrating and gathering this information is a tedious, cumbersome, error-prone process when done manually, especially for large projects.  ...  transitive closure algorithm would be required.  ... 
doi:10.1145/1985429.1985437 fatcat:ejngllgsbzbh7c4l5o356uag64
« Previous Showing results 1 — 15 out of 1,167 results