Filters








366 Hits in 4.2 sec

Aggregate queries in peer-to-peer OLAP

Mauricio Minuto Espil, Alejandro A. Vaisman
2004 Proceedings of the 7th ACM international workshop on Data warehousing and OLAP - DOLAP '04  
Because a multidimensional database normally consists in a collection of views of aggregated data, a careful translation process is needed in this case, in order to transform any summary concept that appears  ...  We present a model for multidimensional data distributed in a P2P network, and a query rewriting technique, that allows a local peer to propagate OLAP queries among its acquaintances, obtaining a meaningful  ...  We characterize P2P OLAP queries as a set of datalog rules with aggregation. Based on this characteriza-tion, we discuss an evaluation procedure for these queries.  ... 
doi:10.1145/1031763.1031782 dblp:conf/dolap/EspilV04 fatcat:wkcsqha2f5c7lmjfgzyjufyapu

Query optimization for OLAP-XML federations

Dennis Pedersen, Karsten Riis, Torben Bach Pedersen
2002 Proceedings of the 5th ACM international workshop on Data Warehousing and OLAP - DOLAP '02  
Furthermore, the performance of the optimized federation queries is comparable to the performance achieved with physical integration of the data, showing that our federated OLAP approach is indeed a feasible  ...  In this paper we present novel techniques for query optimization in federations of OLAP and XML databases.  ...  These efforts include both rule based and cost based optimization techniques.  ... 
doi:10.1145/583890.583899 dblp:conf/dolap/PedersenRP02 fatcat:k4txlt34pzbzlff6l7amil5sji

Semantic Metadata for Supporting Exploratory OLAP [article]

Jovan Varga
2016 Ph.d.-serien for Det Teknisk-Naturvidenskabelige Fakultet, Aalborg Universitet  
The layout of the paper has been revised.  ...  Thus, based on a survey of existing user assistance approaches in the OLAP domain, Chapter 2 defined the analytical metadata framework which identified the metadata artifacts used in this context.  ...  A key feature to promote the use of our proposal is to relieve OLAP users from the need of learning a new and complex language like SPARQL.  ... 
doi:10.5278/vbn.phd.engsci.00172 fatcat:2jvgnvvmznh7dk7dap2aipiiii

OLAP over Continuous Domains via Density-Based Hierarchical Clustering [chapter]

Michelangelo Ceci, Alfredo Cuzzocrea, Donato Malerba
2011 Lecture Notes in Computer Science  
A clear advantage of this emerging approach is that of avoiding the beforehand definition of an ad-hoc discretization hierarchy along each OLAP dimension.  ...  Following this latest trend, in this paper we propose a novel method for effectively and efficiently supporting roll-up and drill-down operations over OLAP data cubes with continuous dimensions via a density-based  ...  changes among fixed collections of cube cells; (v) [17] , which proposes a framework for mining inter-dimensional association rules from data cubes on the basis of SUM-based aggregate measures as a crucial  ... 
doi:10.1007/978-3-642-23863-5_57 fatcat:wd2kwi24ffdhhamohe4ozu2giq

A survey of logical models for OLAP databases

Panos Vassiliadis, Timos Sellis
1999 SIGMOD record  
This work is supported by the European Commission in ESPRIT Long Term Research Project DWQ (Foundations of Data Warehouse Quality). We would also like to thank Prof. Matthias Jarke.  ...  These queries do not fit the pattern of typical OLAP operations, which are sequential and interactive in their nature. Currently, a revision of the benchmark is under preparation.  ...  OLAP databases could not escape from this rule; several conceptual (e.g. [BaSa98], [Kimb96] ) and physical (e.g.  ... 
doi:10.1145/344816.344869 fatcat:jkxbaaus7fatdprh5brv75sbui

Efficient intensional redefinition of aggregation hierarchies in multidimensional databases

Mauricio Minuto Espil, Alejandro A. Vaisman
2001 Proceedings of the 4th ACM international workshop on Data warehousing and OLAP - DOLAP '01  
Programs in IRAH consist of intensional rules, which can be regarded as patterns for: (a) overriding natural composition between rollup functions on adjacent levels in the concept hierarchy, (b) canceling  ...  Finally, we present an algorithm that computes the revised dimension in polynomial time, although under more realistic assumptions, complexity becomes linear on the number of paths in the hierarchy of  ...  In models for OLAP [5, 15] , data is represented as a set of dimensions and fact tables. Dimensions are usually organized as hierarchies, supporting different levels of data aggregation.  ... 
doi:10.1145/512236.512237 dblp:conf/dolap/EspilV01 fatcat:windj7q6dnh5lgl4gijvw7esji

Towards Introducing User Preferences in OLAP Reporting Tool [chapter]

Natalija Kozmina, Darja Solodovnikova
2012 Lecture Notes in Business Information Processing  
This paper presents an OLAP reporting tool and an approach for determining and processing user OLAP preferences, which are useful for generating recommendations on potentially interesting reports.  ...  The methods for processing schema-specific and report-specific OLAP preferences are outlined.  ...  In this paper we present a revised version of the metamodel, previous versions of which are published in [14] , [15] .  ... 
doi:10.1007/978-3-642-29231-6_17 fatcat:q3z3a6sd2naktfsp4plonivuzi

Sub Table Based Access Security Model (STBAM) for OLAP Tools

Abid Sohail, Khalid Hassain
2013 International Journal of Computer and Communication Engineering  
We have developed a Sub- Table Based Access Model (STBAM) at the presentation layer of OLAP.  ...  based on the operations of OLAP tools.  ... 
doi:10.7763/ijcce.2013.v2.266 fatcat:ac2u2oct5zfofmydjlghffloy4

Sigma Worksheet: Interactive Construction of OLAP Queries [article]

James Gale and Max Seiden and Gretchen Atwood and Jason Frantz and Rob Woollen and Çağatay Demiralp
2021 arXiv   pre-print
Finally, to assess the usefulness of Sigma Worksheet in deployment, we elicit feedback through a 100-person survey followed by a semi-structured interview study with 70 participants.  ...  Here we introduce Sigma Worksheet, a new interactive system that enables users to easily perform ad-hoc visual analysis of data in CDWs at scale.  ...  Sigma Worksheet is a product of their labor, care, and dedication. We also thank the early users of Sigma for teaching us so much and having patience with our bugs.  ... 
arXiv:2012.00697v3 fatcat:xezl2ygjrfhghg6tcrzzgegigi

Cost Modeling and Estimation for OLAP-XML Federations [chapter]

Dennis Pedersen, Karsten Riis, Torben Bach Pedersen
2002 Lecture Notes in Computer Science  
On top of the algebra, a SQL-based OLAP query language, SQL , has been defined.  ...  In an efficient implementation, cost-based optimization is a must, creating a need for an effective cost model for OLAP-XML federations. However, existing cost models do not support such systems.  ...  tree, as the rule-based approach will always find the best solution.  ... 
doi:10.1007/3-540-46145-0_24 fatcat:mza4tajshrauvj2g7ivm6eajqq

From Analysis to Interactive Exploration: Building Visual Hierarchies from OLAP Cubes [chapter]

Svetlana Vinnik, Florian Mansmann
2006 Lecture Notes in Computer Science  
We present a novel framework for comprehensive exploration of OLAP data by means of user-defined dynamic hierarchical visualizations.  ...  Special effort has been invested in handling non-trivial relationships (e.g., mixed granularity) within hierarchical dimensions in a way transparent to the user.  ...  OLAP Cube as a Decomposition Tree OLAP operations, such as drill-down, roll-up, and cube, transform the data from a fact table into a hierarchy by aggregating or disaggregating the measure along specified  ... 
doi:10.1007/11687238_31 fatcat:afih6apckrfslhqp4xzszw7bue

A knowledge-based framework for a mobile OLAP system

Nachida Rezoug, Omar Boussaid, Fahima Nader
2015 International Journal of Decision Support Systems  
We propose in this paper a knowledge-based framework for a mobile OLAP. Its main goal is to allow decision-makers to, efficiently, access datasets in OLAP system anywhere and anytime.  ...  This paper is a revised and expanded version of a paper entitled 'A contextual personalized recommender system for mobile OLAP' presented at the Information Technology and E-service (ICITes), Sousse, Tunis  ...  In order to deal with all three context categories (preferences, context and capability context), we use a hybrid recommendation approach exploiting content-based methods, Bayesian classifier, and rule-based  ... 
doi:10.1504/ijdss.2015.067276 fatcat:d2oshgn4urcxbc5th3mhusvj2u

QB4MobOLAP: A Vocabulary Extension for Mobility OLAP on the Semantic Web

Irya Wisnubhadra, Safiza Kamal Baharin, Nurul A. Emran, Djoko Budiyanto Setyohadi
2021 Algorithms  
Mobility OLAP makes use of trajectory data warehousing techniques, which typically include a path of moving objects at a particular point in time.  ...  As a result, QB4MobOLAP vocabulary and the Mobility OLAP operators are evaluated by applying them to a practical use case of transportation analysis involving 8826 triples consisting of approximately 7000  ...  Acknowledgments: We would like to acknowledge the support received from Computational Intelligence and Technologies (CIT) group in Universiti Teknikal Malaysia Melaka.  ... 
doi:10.3390/a14090265 fatcat:frj6asekqjfuvd5cvz6pqej2zq

Effectively and efficiently supporting roll-up and drill-down OLAP operations over continuous dimensions via hierarchical clustering

Michelangelo Ceci, Alfredo Cuzzocrea, Donato Malerba
2013 Journal of Intelligent Information Systems  
Following this research trend, in this paper we propose a novel method, founded on a density-based hierarchical clustering algorithm, to support roll-up and drill-down operations over OLAP data cubes with  ...  Abstract In traditional OLAP systems, roll-up and drill-down operations over data cubes exploit fixed hierarchies defined on discrete attributes, which play the roles of dimensions, and operate along them  ...  This work is in partial fulfillment of the requirements of the Italian project VINCENTE PON02_00563_3470993 "A Virtual collective INtelligenCe ENvironment to develop sustainable Technology Entrepreneurship  ... 
doi:10.1007/s10844-013-0268-1 fatcat:cnjmsppqbzfh3kh4q5xbrn2fte

Fuzzy OLAP Association Rules Mining-Based Modular Reinforcement Learning Approach for Multiagent Systems

M. Kaya, R. Alhajj
2005 IEEE Transactions on Systems Man and Cybernetics Part B (Cybernetics)  
In this study, we propose a novel multiagent learning approach to handle these problems. Our approach is based on utilizing the mining process for modular cooperative learning systems.  ...  Second, we present a new action selection model, which is also based on association rules mining.  ...  SUMMARY AND CONCLUSIONS In this paper, we proposed a novel multiagent reinforcement learning approach based on fuzzy OLAP association rules mining.  ... 
doi:10.1109/tsmcb.2004.843278 pmid:15828660 fatcat:3jzot57rwreyhlobrdqyz6obfq
« Previous Showing results 1 — 15 out of 366 results