Filters








33,216 Hits in 2.6 sec

Efficient evaluation for a subset of recursive queries

G. Grahne, S. Sippu, E. Soisalon-Soininen
1987 Proceedings of the sixth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '87  
Well-known results on graph traversal are used to develop a practical, efficient algorithm for evaluating regularly and linearly recursive queries in databases that contain only binary relations.  ...  Transformations are given that reduce a subset of regular and linear queries involving n-ary relations (n > 2) to queries lnvolvlng only binary relatloqs.  ...  Kuittinen has implemented a system for evaluating binary relational exoressions [IO]  ... 
doi:10.1145/28659.28690 dblp:conf/pods/GrahneSS87 fatcat:7a7waqgxozcwxetol4zldqvjjy

Efficient evaluation for a subset of recursive queries

Gösta Grahne, Seppo Sippu, Eljas Soisalon-Soininen
1991 The Journal of Logic Programming  
The magic-sets optimization strategy in its generalized form 151 applies to any kind of recursion, but the computation of the magic sets can be made easy only in the case of linear EVALUATION FOR A SUBSET  ...  An algorithm for recursive query evaluation is usually organized so that it carries along a vector of intermediate relations representing the current state of the evaluation.  ...  CONCLUSION We have presented an efficient strategy for evaluating a subset of regularly and linearly recursive queries in logic databases.  ... 
doi:10.1016/0743-1066(91)90039-r fatcat:zjjbx6cbozgrlmiyopgdaxgqp4

Maintenance of Recursive Views [chapter]

Suzanne W. Dietrich
2017 Encyclopedia of Database Systems  
A disadvantage of this bottom-up approach for evaluating a query is that the entire view is computed even when a query may be asking for a small subset of the data.  ...  Evaluation of Recursive Queries Initial research in the area emphasized the efficient and complete evaluation of recursive queries.  ...  (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

Efficient recursive query processing using wavefront methods

C.T. Yu, Weining Zhang
1987 1987 IEEE Third International Conference on Data Engineering  
(ii) A characterization of the expressions generated by linear recursive rules is given. Properties of the ~expressions will be useful for efficient processing of linear recursive queries.  ...  (i) In spite of seemingly masonable approach of the wavefront methods, certain linear recursive queries are not processed efficiently or correctly.  ...  Properties of the expressions will be useful for efficient processing of linear recursive queries. where R(x I . . . . .  ... 
doi:10.1109/icde.1987.7272435 dblp:conf/icde/YuZ87 fatcat:5gmedstmr5hc5kzie5wxmiheku

Title index to volume 10

1991 The Journal of Logic Programming  
Set Grammars: A Formalism for Prob- lem Solving, 1 Efficient Evaluation for a Subset of Recursive Queries, 301 Enhancing Unification in PROLOG Through Clause In- dexing, 23 On-Line Algorithms  ...  Language, 181 Simple Characterization of Uniform Roundedness for a Class of Recursions, A, 233  ... 
doi:10.1016/0743-1066(91)90041-m fatcat:7v37o4jw3vapjkbmrfmfbowt6a

Database logic programming

MosheY. Vardi
1991 The Journal of Logic Programming  
The next two papers deal with optimization of database logic programs. The paper "A Simple Characterization of Uniform Boundedness for a Class of Recursions", by J. F. Naughton and Y.  ...  Sagiv, deals with the detection of bounded recursion (i.e., recursion that has a data-independent bound on its depth).  ...  The last two papers deal with the complexity of evaluating database logic programs. The paper "Efficient Evaluation for a Subset of Recursive Queries", by G. Grahne, S. Sippu, and E.  ... 
doi:10.1016/0743-1066(91)90035-n fatcat:kizazk7lrna2tmf4tj6hjvb2gm

Volume contents to volume 10

1991 The Journal of Logic Programming  
Naughton and Yehoshua Sagiv ON THE POWER OF MAGIC Catriel Beeri and Raghu Ramakrishnan EFFICIENT EVALUATION FOR A SUBSET OF RECURSIVE QUERIES Gijsta Grahne, Seppo Sippu, and Eljas Soisalon-Soininen  ...  Vardi SET CONSTRUCTORS IN A LOGIC DATABASE LANGUAGE Catriel Beeri, Shamim Naqvi, Oded Shmueli, and Shalom Tsur A SIMPLE CHARACTERIZATION OF UNIFORM BOUNDEDNESS FOR A CLASS OF RECURSIONS Jeffrey F  ... 
doi:10.1016/0743-1066(91)90043-o fatcat:q73tqcvapzgt3eechpeage2dla

Capability-sensitive query processing on Internet sources

H. Garcia-Molina, W. Labio, R. Yerneni
1999 Proceedings 15th International Conference on Data Engineering (Cat. No.99CB36337)  
take advantage of the source capabilities; and (3) the plans are more efficient since a larger space of plans is examined.  ...  In this paper, we present a scheme called GenCompact for generating capability-sensitive plans for queries on Internet sources.  ...  For instance, c 3 can be locally evaluated on the result of the source query SPc 2 ; A Attrc 3 ; R that supports the subset fc 2 g.  ... 
doi:10.1109/icde.1999.754897 dblp:conf/icde/Garcia-MolinaLY99 fatcat:l7tknumd7bdqnjy4cd7smqp6rq

Optimizing subset queries

Cyrille Masson, Céline Robardet, Jean-François Boulicaut
2004 Proceedings of the 2004 ACM symposium on Applied computing - SAC '04  
Our experiments show an interesting improvement for these useful subset queries.  ...  Storing sets and querying them (e.g., subset queries that provide all supersets of a given set) is known to be difficult within relational databases.  ...  The authors thank Sophie Rome, Hubert Vidal and Jérémy Besson for the microarray data, the discretized matrix and the extracted closed itemsets.  ... 
doi:10.1145/967900.968013 dblp:conf/sac/MassonRB04 fatcat:ehti4ix3pbhlxhbikpd3m5vfqq

Optimization of Linear Recursive Queries in SQL

Carlos Ordonez
2010 IEEE Transactions on Knowledge and Data Engineering  
Recursion is a fundamental computation mechanism which has been incorporated into SQL. This work focuses on the optimization of linear recursive queries in SQL.  ...  Five query optimizations are studied: (1) Storage and indexing; (2) early selection; (3) early evaluation of non-recursive joins; (4) pushing duplicate elimination; (5) pushing aggregation.  ...  A path is defined as a subset of E linking two vertices in V .  ... 
doi:10.1109/tkde.2009.83 fatcat:qopingnlorfdhlnlygjrbcj6ly

Optimizing recursive queries in SQL

Carlos Ordonez
2005 Proceedings of the 2005 ACM SIGMOD international conference on Management of data - SIGMOD '05  
In general, the proposed optimizations produce a significant reduction in the evaluation time of recursive queries.  ...  To provide an abstract framework for discussion, we focus on computing the transitive closure of a graph.  ...  Efficient evaluation of recursive queries is a classic and broad topic in the database literature. Most work has been theoretical or in the context of deductive databases.  ... 
doi:10.1145/1066157.1066260 dblp:conf/sigmod/Ordonez05 fatcat:shxhnniqdnffxixfj6hwf36k3e

Index structures for matching XML twigs using relational query processors

Zhiyuan Chen, Johannes Gehrke, Flip Korn, Nick Koudas, Jayavel Shanmugasundaram, Divesh Srivastava
2007 Data & Knowledge Engineering  
The experimental results show that our novel indices achieve orders of magnitude improvement in performance for evaluating twig queries, albeit at a higher space cost, over the use of previously proposed  ...  However, existing XML path indices suffer from at least one of three limitations: they focus only on indexing the structure (relying on a separate index for node content), they are useful only for simple  ...  Please refer to [3] for details. Conclusion We have described a family of index structures, with different space-time tradeoffs, for the efficient evaluation of ad hoc, recursive, twig queries.  ... 
doi:10.1016/j.datak.2006.03.003 fatcat:wtbf2xcvuffcln725m552hpwya

Index Structures for Matching XML Twigs Using Relational Query Processors

Zhiyuan Chen, J. Gehrke, F. Korn, N. Koudas, J. Shanmugasundaram, D. Srivastava
2005 21st International Conference on Data Engineering Workshops (ICDEW'05)  
The experimental results show that our novel indices achieve orders of magnitude improvement in performance for evaluating twig queries, albeit at a higher space cost, over the use of previously proposed  ...  However, existing XML path indices suffer from at least one of three limitations: they focus only on indexing the structure (relying on a separate index for node content), they are useful only for simple  ...  Please refer to [3] for details. Conclusion We have described a family of index structures, with different space-time tradeoffs, for the efficient evaluation of ad hoc, recursive, twig queries.  ... 
doi:10.1109/icde.2005.231 dblp:conf/icde/ChenGK05a fatcat:bbvornl7oza6nll3raklpe7x7i

Page 2807 of Mathematical Reviews Vol. , Issue 92e [page]

1992 Mathematical Reviews  
In this paper we identify a useful subset of recursive definitions, the one-sided recursions.  ...  We show how to detect one-sided recursions, and give a schema to evaluate selections of the form ‘column = constant’ on a relation defined by a one-sided recursion.  ... 

vSPARQL: A view definition language for the semantic web

Marianne Shaw, Landon T. Detwiler, Natalya Noy, James Brinkley, Dan Suciu
2011 Journal of Biomedical Informatics  
We evaluate the expressivity of our approach by defining views for practical use cases and comparing our view definition language to existing query languages.  ...  We present a general solution for RDF information set reuse inspired by database views.  ...  We thank Nicki Dell for feedback on the manuscript, and Onard Mejino, Dan Cook, and Max Neal for help in defining the views.  ... 
doi:10.1016/j.jbi.2010.08.008 pmid:20800106 pmcid:PMC3042057 fatcat:7anb7nvu25fr7ki5acp6pb2vii
« Previous Showing results 1 — 15 out of 33,216 results