702 research outputs found

    Data Mining-based Fragmentation of XML Data Warehouses

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    With the multiplication of XML data sources, many XML data warehouse models have been proposed to handle data heterogeneity and complexity in a way relational data warehouses fail to achieve. However, XML-native database systems currently suffer from limited performances, both in terms of manageable data volume and response time. Fragmentation helps address both these issues. Derived horizontal fragmentation is typically used in relational data warehouses and can definitely be adapted to the XML context. However, the number of fragments produced by classical algorithms is difficult to control. In this paper, we propose the use of a k-means-based fragmentation approach that allows to master the number of fragments through its kk parameter. We experimentally compare its efficiency to classical derived horizontal fragmentation algorithms adapted to XML data warehouses and show its superiority

    Hybrid Solution for Integrated Trading

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    Integrated applications are complex solutions, whose complexity are determined by the economic processes they implement, the amount of data employed (millions of records grouped in hundreds of tables, databases, hundreds of GB) and the number of users. Service oriented architecture (SOA), is now the most talked-about integration solution in mainstream journals, addressing both simple applications, for a department but also at enterprise level. SOA can refer to software architecture or to a way of standardizing the technical architecture of an enterprise and it shows its value when operating in several distinct and heterogeneous environments.System Integration, Data Integration, Web Services, Java, XML, Stock Market

    Solutions for decision support in university management

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    The paper proposes an overview of decision support systems in order to define the role of a system to assist decision in university management. The authors present new technologies and the basic concepts of multidimensional data analysis using models of business processes within the universities. Based on information provided by scientific literature and on the authors’ experience, the study aims to define selection criteria in choosing a development environment for designing a support system dedicated to university management. The contributions consist in designing a data warehouse model and models of OLAP analysis to assist decision in university management.university management, decision support, multidimensional analysis, data warehouse, OLAP

    A Methodology and Tool for Rapid Prototyping of Data Warehouses using Data Mining: Application to Birds Biodiversity

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    International audienceData Warehouses (DWs) are large repositories of data aimed at supporting the decision-making process by enabling flexible and interactive analyses via OLAP systems. Rapid prototyping of DWs is necessary when OLAP applications are complex. Some work about the integration of Data Mining and OLAP systems has been done to enhance OLAP operators with mined indicators, and/or to define the DW schema. However, to best of our knowledge, prototyping methods for DWs do not support this kind of integration. Then, in this paper we present a new prototyping methodology for DWs, extending [3], where DM methods are used to define the DW schema. We validate our approach on a real data set concerning bird biodiversity

    Framework for Interoperable and Distributed Extraction-Transformation-Loading (ETL) Based on Service Oriented Architecture

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    Extraction. Transformation and Loading (ETL) are the major functionalities in data warehouse (DW) solutions. Lack of component distribution and interoperability is a gap that leads to many problems in the ETL domain, which is due to tightly-coupled components in the current ETL framework. This research discusses how to distribute the Extraction, Transformation and Loading components so as to achieve distribution and interoperability of these ETL components. In addition, it shows how the ETL framework can be extended. To achieve that, Service Oriented Architecture (SOA) is adopted to address the mentioned missing features of distribution and interoperability by restructuring the current ETL framework. This research contributes towards the field of ETL by adding the distribution and inter- operability concepts to the ETL framework. This Ieads to contributions towards the area of data warehousing and business intelligence, because ETL is a core concept in this area. The Design Science Approach (DSA) and Scrum methodologies were adopted for achieving the research goals. The integration of DSA and Scrum provides the suitable methods for achieving the research objectives. The new ETL framework is realized by developing and testing a prototype that is based on the new ETL framework. This prototype is successfully evaluated using three case studies that are conducted using the data and tools of three different organizations. These organizations use data warehouse solutions for the purpose of generating statistical reports that help their top management to take decisions. Results of the case studies show that distribution and interoperability can be achieved by using the new ETL framework

    MaxPart: An Efficient Search-Space Pruning Approach to Vertical Partitioning

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    Vertical partitioning is the process of subdividing the attributes of a relation into groups, creating fragments. It represents an effective way of improving performance in the database systems where a significant percentage of query processing time is spent on the full scans of tables. Most of proposed approaches for vertical partitioning in databases use a pairwise affinity to cluster the attributes of a given relation. The affinity measures the frequency of accessing simultaneously a pair of attributes. The attributes having high affinity are clustered together so as to create fragments containing a maximum of attributes with a strong connectivity. However, such fragments can directly and efficiently be achieved by the use of maximal frequent itemsets. This technique of knowledge engineering reflects better the closeness or affinity when more than two attributes are involved. The partitioning process can be done faster and more accurately with the help of such knowledge discovery technique of data mining. In this paper, an approach based on maximal frequent itemsets to vertical partitioning is proposed to efficiently search for an optimized solution by judiciously pruning the potential search space. Moreover, we propose an analytical cost model to evaluate the produced partitions. Experimental studies show that the cost of the partitioning process can be substantially reduced using only a limited set of potential fragments. They also demonstrate the effectiveness of our approach in partitioning small and large tables

    A review of the state of the art in Machine Learning on the Semantic Web: Technical Report CSTR-05-003

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    A unified view of data-intensive flows in business intelligence systems : a survey

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    Data-intensive flows are central processes in today’s business intelligence (BI) systems, deploying different technologies to deliver data, from a multitude of data sources, in user-preferred and analysis-ready formats. To meet complex requirements of next generation BI systems, we often need an effective combination of the traditionally batched extract-transform-load (ETL) processes that populate a data warehouse (DW) from integrated data sources, and more real-time and operational data flows that integrate source data at runtime. Both academia and industry thus must have a clear understanding of the foundations of data-intensive flows and the challenges of moving towards next generation BI environments. In this paper we present a survey of today’s research on data-intensive flows and the related fundamental fields of database theory. The study is based on a proposed set of dimensions describing the important challenges of data-intensive flows in the next generation BI setting. As a result of this survey, we envision an architecture of a system for managing the lifecycle of data-intensive flows. The results further provide a comprehensive understanding of data-intensive flows, recognizing challenges that still are to be addressed, and how the current solutions can be applied for addressing these challenges.Peer ReviewedPostprint (author's final draft

    NOSQL design for analytical workloads: Variability matters

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    Big Data has recently gained popularity and has strongly questioned relational databases as universal storage systems, especially in the presence of analytical workloads. As result, co-relational alternatives, commonly known as NOSQL (Not Only SQL) databases, are extensively used for Big Data. As the primary focus of NOSQL is on performance, NOSQL databases are directly designed at the physical level, and consequently the resulting schema is tailored to the dataset and access patterns of the problem in hand. However, we believe that NOSQL design can also benefit from traditional design approaches. In this paper we present a method to design databases for analytical workloads. Starting from the conceptual model and adopting the classical 3-phase design used for relational databases, we propose a novel design method considering the new features brought by NOSQL and encompassing relational and co-relational design altogether.Peer ReviewedPostprint (author's final draft
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