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Query Evaluation and Optimization in the Semantic Web [article]

Edna Ruckhaus, Eduardo Ruiz, Maria-Esther Vidal
2007 arXiv   pre-print
A cost-based query optimization technique for DOB is presented. A hybrid cost model is proposed to estimate the cost and cardinality of basic and inferred facts.  ...  Cardinality and cost of inferred facts are estimated using an adaptive sampling technique, while techniques of traditional relational cost models are used for estimating the cost of basic facts and conjunctive  ...  Traditional query optimization techniques for deductive databases systems include join-ordering strategies, and techniques that combine a bottom-up evaluation with top-down propagation of query variable  ... 
arXiv:0711.2087v1 fatcat:hrclzxps3rhphjxutgz5mes6jm

Special issue on best papers of VLDB 2015

Chen Li, Volker Markl
2016 The VLDB journal  
For self-join-free conjunctive queries, there is only a single plan, in which case the authors show that the query evaluation is in PTIME. The paper "Fast and Scalable Inequality Joins"  ...  The paper "Dissociation and Propagation for Approximate Lifted Inference with Standard Relational Database Management Systems" by Wolfgang Gatterbauer and Dan Suciu focuses on the approximate evaluation  ...  DeepDive, a system that combines database and machine learning ideas to help develop inference-based knowledge-base construction systems.  ... 
doi:10.1007/s00778-016-0450-5 fatcat:bs244b7w6fbflnahsx5cctaqfi

Knowledge extraction from professional e-mails

Nada Matta, Hassan Atifi, François Rauscher
2014 Proceedings of the 2014 Federated Conference on Computer Science and Information Systems  
Some professional e-mails contain knowledge about how actor face problem in order to realize projects. This type of knowledge is produced in cooperative activity.  ...  So the main questions of our research are: • Can we extract knowledge from professional e-mails? • If so, which type of knowledge can be represented? • How to link this knowledge to project memory?  ...  We use pragmatics analysis and knowledge engineering techniques for this aim. II.  ... 
doi:10.15439/2014f161 dblp:conf/fedcsis/MattaAR14 fatcat:2dzcu6lcz5fu7fnynky6nwilli

Query Selectivity Estimation via Data Mining [chapter]

Jarek Gryz, Dongming Liang
2004 Intelligent Information Processing and Web Mining  
Yet, there are few efficient techniques that solve this problem. We propose a new approach to join selectivity estimation.  ...  We present experimental results indicating that empty joins are common in real data sets and propose a simple strategy that uses information about empty joins for an improved join selectivity estimation  ...  The maintanance of empty joins should also be straightforward as DB2 already supports deferred maintanance of materialized views [10] .  ... 
doi:10.1007/978-3-540-39985-8_4 fatcat:7ykywnvc4vhodgdejbvzpk4br4

OnEQL: An Ontology Efficient Query Language Engine for the Semantic Web

Edna Ruckhaus, Maria-Esther Vidal, Eduardo Ruiz
2007 International Conference on Logic Programming  
In the first stage, a dynamic programming-based algorithm is used to identify an ordering of predicates in the query that minimizes its estimated evaluation cost.  ...  In this paper we describe the OnEQL system, a query engine that implements optimization techniques and evaluation strategies to speed up the evaluation time of querying and reasoning services in the Semantic  ...  The OnEQL System The OnEQL system develops evaluation strategies, and cost-based and heuristicbased optimization techniques for Web ontologies.  ... 
dblp:conf/iclp/RuckhausVR07 fatcat:e7lxvv2qgzftbh5eezd2fi6ng4

Special issue on best papers of VLDB 2016

Surajit Chaudhuri, Jayant R. Haritsa
2018 The VLDB journal  
Although primarily focused on main-memory systems, the paper also studies disk-based systems.  ...  These techniques include mechanisms for the sharing of join results, and the deployment of efficient data structures well suited to multi-threaded query executions.  ...  Although primarily focused on main-memory systems, the paper also studies disk-based systems.  ... 
doi:10.1007/s00778-018-0520-y fatcat:mhur7ad2erft5avvhswlqfwfyi

Query evaluation and optimization in the semantic web

EDNA RUCKHAUS, EDUARDO RUIZ, MARÍA-ESTHER VIDAL
2008 Theory and Practice of Logic Programming  
A cost-based query optimization technique for DOB is presented. A hybrid cost model is proposed to estimate the cost and cardinality of basic and inferred facts.  ...  Cardinality and cost of inferred facts are estimated using an adaptive sampling technique, while techniques of traditional relational cost models are used for estimating the cost of basic facts and conjunctive  ...  Traditional query optimization techniques for deductive databases systems include join-ordering strategies, and techniques that combine a bottom-up evaluation with top-down propagation of query variable  ... 
doi:10.1017/s1471068407003225 fatcat:4b7kwjrhejgotasvkq35t5gdtm

Towards a Unified Graph Model for Supporting Data Management and Usable Machine Learning

Guoliang Li, Meihui Zhang, Beng Chin Ooi
2017 IEEE Data Engineering Bulletin  
To optimize data management procedures, we devise graph optimization techniques to support a finer-grained optimization than traditional tree-based optimization model.  ...  This calls for a reexamination of database design to make it machine learning friendly.  ...  We outlined graph-based optimization techniques to improve the performance, which provides a finergrained optimization than traditional tree-based optimization model.  ... 
dblp:journals/debu/0001ZO17 fatcat:as2ebadiz5aerllir3ejbd3y74

Mining Rules Incrementally over Large Knowledge Bases [article]

Xiaofeng Zhou, Ali Sadeghian, Daisy Zhe Wang
2019 arXiv   pre-print
To the best of our knowledge, our incremental rule mining system is the first that handles updates to web-scale knowledge bases.  ...  quality; we apply multiple optimization techniques that reduce runtime by more than 2 orders of magnitude.  ...  The authors would also like to thank Anthony Colas, Caleb Bryant and anonymous reviewers for their comments on this paper.  ... 
arXiv:1904.09399v1 fatcat:vq74ubhjebccpcvlhh7p4xplpm

Effects of Database Size on Rule System Performance: Five Case Studies

David A. Brant, Timothy Grose, Bernie J. Lofaso, Daniel P. Miranker
1991 Very Large Data Bases Conference  
Common techniques used in the design of rule-based systems store large amounts of state in order to derive precise query support information that will enable better performance.  ...  These techniques were intended for use in main memory on small data sets and are not ncccssarily suited for a database environment.  ...  The Rete algorithm is the basis for most rule-based systems in use today.  ... 
dblp:conf/vldb/BrantGLM91 fatcat:45larv4sanffrg2x47sft3nqoq

Emergent Communities for Semantic Collaboration in Multi-Knowledge Environments: Methods and Techniques

Stefano Montanelli
2006 International Conference on Advanced Information Systems Engineering  
The Ph.D. thesis abstract illustrates a semantic handshake process based on ontologies and ontology matching techniques to handle consensus negotiation and peer community formation.  ...  The need of sharing data and resources to foster semantic collaboration is a key problem at the current stage of development of open distributed systems.  ...  This is typical for instance of peer-based systems, characterized by a set of independent peer parties without prior reciprocal knowledge and no degree of relationship, that dynamically need to cooperate  ... 
dblp:conf/caise/Montanelli06 fatcat:f2aqzdhnu5cpnbt2uufpzumzam

Knowledge Extraction from Professional E-mails [chapter]

Nada Matta, Hassan Atifi, François Rauscher
2015 IFIP Advances in Information and Communication Technology  
Some professional e-mails contain knowledge about how actor face problem in order to realize projects. This type of knowledge is produced in cooperative activity.  ...  So the main questions of our research are: • Can we extract knowledge from professional e-mails? • If so, which type of knowledge can be represented? • How to link this knowledge to project memory?  ...  We use pragmatics analysis and knowledge engineering techniques for this aim. II.  ... 
doi:10.1007/978-3-319-28868-0_3 fatcat:2quwuegqtnhfngn3vfn4w3j75y

Traversing Knowledge Graphs with Good Old (and New) Joins

Paolo Atzeni, Luigi Bellomarini, Davide Benedetto, Emanuel Sallinger
2020 European Conference on Artificial Intelligence  
Specifically, we implement our results in the vadalog System [3] , a state-of-the-art knowledge graph management systems and conduct experimental evaluation.  ...  This is leading to the rise of systems and tools able to facilitate graph data modeling, processing and analysis, with prominent AI companies developing core systems based on the property graph model  ... 
dblp:conf/ecai/AtzeniBBS20 fatcat:rqyinx73ujbhvhchjskdmw56i4

Database Foundations for Scalable RDF Processing [chapter]

Katja Hose, Ralf Schenkel, Martin Theobald, Gerhard Weikum
2011 Lecture Notes in Computer Science  
The first part of the lecture will introduce state-of-the-art techniques for scalably storing and querying RDF with relational systems, including alternatives for storing RDF, efficient index structures  ...  We cover search engines as well as federated query processing, highlight differences to classic federated database systems, and discuss efficient techniques for distributed query processing in general  ...  For optimization in distributed RDF systems, join order optimization corresponds to determining the order of evaluating basic graph patterns.  ... 
doi:10.1007/978-3-642-23032-5_4 fatcat:5owq3argizaj3epzu4yhuuxc6i

Linked Data Query Processing Strategies [chapter]

Günter Ladwig, Thanh Tran
2010 Lecture Notes in Computer Science  
Additionally, we propose the adoption of stream-based query processing to deal with the unpredictable nature of data access in the distributed Linked Data environment.  ...  To exploit knowledge discovered at run-time, we propose an additional step, explicitly scheduled during query processing, called correct source ranking.  ...  The federated system assumes that all source descriptions are available and based on that, compiles a query evaluation plan that specifies the relevant sources, and the order for retrieving and processing  ... 
doi:10.1007/978-3-642-17746-0_29 fatcat:u5ikuthbkjaq5pvodihrlmhecy
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