1,402 research outputs found

    A Survey of Parallel Data Mining

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    With the fast, continuous increase in the number and size of databases, parallel data mining is a natural and cost-effective approach to tackle the problem of scalability in data mining. Recently there has been a considerable research on parallel data mining. However, most projects focus on the parallelization of a single kind of data mining algorithm/paradigm. This paper surveys parallel data mining with a broader perspective. More precisely, we discuss the parallelization of data mining algorithms of four knowledge discovery paradigms, namely rule induction, instance-based learning, genetic algorithms and neural networks. Using the lessons learned from this discussion, we also derive a set of heuristic principles for designing efficient parallel data mining algorithms

    Augmenting data warehousing architectures with hadoop

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    Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementAs the volume of available data increases exponentially, traditional data warehouses struggle to transform this data into actionable knowledge. Data strategies that include the creation and maintenance of data warehouses have a lot to gain by incorporating technologies from the Big Data’s spectrum. Hadoop, as a transformation tool, can add a theoretical infinite dimension of data processing, feeding transformed information into traditional data warehouses that ultimately will retain their value as central components in organizations’ decision support systems. This study explores the potentialities of Hadoop as a data transformation tool in the setting of a traditional data warehouse environment. Hadoop’s execution model, which is oriented for distributed parallel processing, offers great capabilities when the amounts of data to be processed require the infrastructure to expand. Horizontal scalability, which is a key aspect in a Hadoop cluster, will allow for proportional growth in processing power as the volume of data increases. Through the use of a Hive on Tez, in a Hadoop cluster, this study transforms television viewing events, extracted from Ericsson’s Mediaroom Internet Protocol Television infrastructure, into pertinent audience metrics, like Rating, Reach and Share. These measurements are then made available in a traditional data warehouse, supported by a traditional Relational Database Management System, where they are presented through a set of reports. The main contribution of this research is a proposed augmented data warehouse architecture where the traditional ETL layer is replaced by a Hadoop cluster, running Hive on Tez, with the purpose of performing the heaviest transformations that convert raw data into actionable information. Through a typification of the SQL statements, responsible for the data transformation processes, we were able to understand that Hadoop, and its distributed processing model, delivers outstanding performance results associated with the analytical layer, namely in the aggregation of large data sets. Ultimately, we demonstrate, empirically, the performance gains that can be extracted from Hadoop, in comparison to an RDBMS, regarding speed, storage usage and scalability potential, and suggest how this can be used to evolve data warehouses into the age of Big Data

    Forecasting the cost of processing multi-join queries via hashing for main-memory databases (Extended version)

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    Database management systems (DBMSs) carefully optimize complex multi-join queries to avoid expensive disk I/O. As servers today feature tens or hundreds of gigabytes of RAM, a significant fraction of many analytic databases becomes memory-resident. Even after careful tuning for an in-memory environment, a linear disk I/O model such as the one implemented in PostgreSQL may make query response time predictions that are up to 2X slower than the optimal multi-join query plan over memory-resident data. This paper introduces a memory I/O cost model to identify good evaluation strategies for complex query plans with multiple hash-based equi-joins over memory-resident data. The proposed cost model is carefully validated for accuracy using three different systems, including an Amazon EC2 instance, to control for hardware-specific differences. Prior work in parallel query evaluation has advocated right-deep and bushy trees for multi-join queries due to their greater parallelization and pipelining potential. A surprising finding is that the conventional wisdom from shared-nothing disk-based systems does not directly apply to the modern shared-everything memory hierarchy. As corroborated by our model, the performance gap between the optimal left-deep and right-deep query plan can grow to about 10X as the number of joins in the query increases.Comment: 15 pages, 8 figures, extended version of the paper to appear in SoCC'1

    Process algebra approach to parallel DBMS performance modelling

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    Abstract unavailable please refer to PD
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