48 research outputs found

    A Novel Hybrid Optimization With Ensemble Constraint Handling Approach for the Optimal Materialized Views

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    The datawarehouse is extremely challenging to work with, as doing so necessitates a significant investment of both time and space. As a result, it is essential to enable rapid data processing in order to cut down on the amount of time needed to respond to queries that are sent to the warehouse. To effectively solve this problem, one of the significant approaches that should be taken is to take the view of materialization. It is extremely unlikely that all of the views that can be derived from the data will ever be materialized. As a result, view subsets need to be selected intelligently in order to enable rapid data processing for queries coming from a variety of locations. The Materialized view selection problem is addressed by the model that has been proposed. The model is based on the ensemble constraint handling techniques (ECHT). In order to optimize the problem, we must take into account the constraints, which include the self-adaptive penalty, the Epsilon ()-parameter, and the stochastic ranking. For the purpose of making a quicker and more accurate selection of queries from the data warehouse, the proposed model includes the implementation of an innovative algorithm known as the constrained hybrid Ebola with COATI optimization (CHECO) algorithm. For the purpose of computing the best possible fitness, the goals of "processing cost of the query," "response cost," and "maintenance cost" are each defined. The top views are selected by the CHECO algorithm based on whether or not the defined fitness requirements are met. In the final step of the process, the proposed model is compared to the models already in use in order to validate the performance improvement in terms of a variety of performance metrics

    Human behavior based particle swarm optimization for materialized view selection in data warehousing environment

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    Because of the Materialized View (MV) space value and repair cost limitation in Data Warehouse (DW) environment, the materialization of all views was practically impossible thus suitable MV selection was one of the smart decisions in building DW to get optimal efficiency, at the same time in the modern world, techniques for enhancing DW quality were appeared continuously such as swarm intelligence. Therefore, this paper presents first framework for speeding up query response time depending on Human Particle Swarm Optimization (HPSO) algorithm for determining the best locations of the views in the DW. The results showed that the proposed method for selecting best MV using HPSO algorithm is better than other algorithms via calculating the ratio of query response time on the base tables of DW and compare it to the response time of the same queries on the MVs. Ratio of implementing the query on the base table takes 14 times more time than the query implementation on the MVs. Where the response time of queries through MVs access equal to 106 milliseconds while by direct access queries equal to 1066 milliseconds. This outlines that the performance of query through MVs access is 1471.698% better than those directly access via DW-logical

    Flexible and scalable digital library search

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    In this report the development of a specialised search engine for a digital library is described. The proposed system architecture consists of three levels: the conceptual, the logical and the physical level. The conceptual level schema enables by its exposure of a domain specific schema semantically rich conceptual search. The logical level provides a description language to achieve a high degree of flexibility for multimedia retrieval. The physical level takes care of scalable and efficient persistent data storage. The role, played by each level, changes during the various stages of a search engine's lifecycle: (1) modeling the index, (2) populating and maintaining the index and (3) querying the index. The integration of all this functionality allows the combination of both conceptual and content-based querying in the query stage. A search engine for the Australian Open tennis tournament website is used as a running example, which shows the power of the complete architecture and its various component

    Space Network Control Conference on Resource Allocation Concepts and Approaches

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    The results are presented of the Space Network Control (SNC) Conference. In the late 1990s, when the Advanced Tracking and Data Relay Satellite System is operational, Space Network communication services will be supported and controlled by the SNC. The goals of the conference were to survey existing resource allocation concepts and approaches, to identify solutions applicable to the Space Network, and to identify avenues of study in support of the SNC development. The conference was divided into three sessions: (1) Concepts for Space Network Allocation; (2) SNC and User Payload Operations Control Center (POCC) Human-Computer Interface Concepts; and (3) Resource Allocation Tools, Technology, and Algorithms. Key recommendations addressed approaches to achieving higher levels of automation in the scheduling process

    Book of Abstracts of the Sixth SIAM Workshop on Combinatorial Scientific Computing

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    Book of Abstracts of CSC14 edited by Bora UçarInternational audienceThe Sixth SIAM Workshop on Combinatorial Scientific Computing, CSC14, was organized at the Ecole Normale Supérieure de Lyon, France on 21st to 23rd July, 2014. This two and a half day event marked the sixth in a series that started ten years ago in San Francisco, USA. The CSC14 Workshop's focus was on combinatorial mathematics and algorithms in high performance computing, broadly interpreted. The workshop featured three invited talks, 27 contributed talks and eight poster presentations. All three invited talks were focused on two interesting fields of research specifically: randomized algorithms for numerical linear algebra and network analysis. The contributed talks and the posters targeted modeling, analysis, bisection, clustering, and partitioning of graphs, applied in the context of networks, sparse matrix factorizations, iterative solvers, fast multi-pole methods, automatic differentiation, high-performance computing, and linear programming. The workshop was held at the premises of the LIP laboratory of ENS Lyon and was generously supported by the LABEX MILYON (ANR-10-LABX-0070, Université de Lyon, within the program ''Investissements d'Avenir'' ANR-11-IDEX-0007 operated by the French National Research Agency), and by SIAM

    Autonomous Database Management at Scale: Automated Tuning, Performance Diagnosis, and Resource Decentralization

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    Database administration has always been a challenging task, and is becoming even more difficult with the rise of public and private clouds. Today, many enterprises outsource their database operation to cloud service providers (CSPs) in order to reduce operating costs. CSPs, now tasked with managing an extremely large number of database instances, cannot simply rely on database administrators. In fact, humans have become a bottleneck in the scalability and profitability of cloud offerings. This has created a massive demand for building autonomous databases—systems that operate with little or zero human supervision. While autonomous databases have gained much attention in recent years in both academia and industry, many of the existing techniques remain limited to automating parameter tuning, backup/recovery, and monitoring. Consequently, there is much to be done before realizing a fully autonomous database. This dissertation examines and offers new automation techniques for three specific areas of modern database management. 1. Automated Tuning – We propose a new generation of physical database designers that are robust against uncertainty in future workloads. Given the rising popularity of approximate databases, we also develop an optimal, hybrid sampling strategy that enables efficient join processing on offline samples, a long-standing open problem in approximate query processing. 2. Performance Diagnosis – We design practical tools and algorithms for assisting database administrators in quickly and reliably diagnosing performance problems in their transactional databases. 3. Resource Decentralization – To achieve autonomy among database components in a shared environment, we propose a highly efficient, starvation-free, and fully decentralized distributed lock manager for distributed database clusters.PHDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/153349/1/dyoon_1.pd

    Indexing methods for web archives

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    There have been numerous efforts recently to digitize previously published content and preserving born-digital content leading to the widespread growth of large text reposi- tories. Web archives are such continuously growing text collections which contain ver- sions of documents spanning over long time periods. Web archives present many op- portunities for historical, cultural and political analyses. Consequently there is a grow- ing need for tools which can efficiently access and search them. In this work, we are interested in indexing methods for supporting text-search work- loads over web archives like time-travel queries and phrase queries. To this end we make the following contributions: • Time-travel queries are keyword queries with a temporal predicate, e.g., “mpii saarland” @ [06/2009], which return versions of documents in the past. We in- troduce a novel index organization strategy, called index sharding, for efficiently supporting time-travel queries without incurring additional index-size blowup. We also propose index-maintenance approaches which scale to such continuously growing collections. • We develop query-optimization techniques for time-travel queries called partition selection which maximizes recall at any given query-execution stage. • We propose indexing methods to support phrase queries, e.g., “to be or not to be that is the question”. We index multi-word sequences and devise novel query- optimization methods over the indexed sequences to efficiently answer phrase queries. We demonstrate the superior performance of our approaches over existing methods by extensive experimentation on real-world web archives.In der jüngsten Vergangenheit gab es zahlreiche Bemühungen zuvor veröffentlichte Inhalte zu digitalisieren und elektronisch erstellte Inhalte zu erhalten. Dies führte zu einem weit verbreitenden Anstieg großer Textdatenbestände. Webarchive sind eine solche Art konstant ansteigender Textdatensammlung. Sie enthalten mehrere Versionen von Dokumenten, welche sich über längere Zeiträume erstrecken. Darüber hinaus bieten sie viele Möglichkeiten für historische, kulturelle und politische Analysen. Infolgedessen gibt es einen wachsenden Bedarf an Werkzeugen, die eine effiziente Suche in Webarchiven und einen effizienten Zugriff auf die Daten erlauben. Der Fokus dieser Arbeit liegt auf Indexierungsverfahren, um die Arbeitslast von Textsuche auf Webarchiven zu unterstützen, wie zum Beispiel time-travel queries oder phrase queries. Zu diesem Zweck leisten wir folgende Beiträge: • Time-travel queries sind Suchwortanfragen mit einem temporalen Prädikat. Zum Beispiel liefert die Anfrage “mpii saarland” @ [06/2009] Versionen des Dokuments aus der Vergangenheit als Ergebnis. Zur effizienten Unterstützung solcher Anfragen ohne die Indexgröße aufzublasen, stellen wir eine neue Strategie zur Organisation von Indizes dar, so genanntes index sharding. Des Weiteren schlagen wir Wartungsverfahren für Indizes vor, die für solch konstant wachsende Datensätze skalieren. • WirentwickelnTechnikenzurAnfrageoptimierungvontime-travelqueries, nachstehend partition selection genannt. Diese maximieren den Recall in jeder Phase der Anfrageverarbeitung. • Wir stellen Indexierungsmethoden vor, die phrase queries unterstützen, z. B. “Sein oder Nichtsein, das ist hier die Frage”. Wir indexieren Sequenzen bestehend aus mehreren Wörtern und entwerfen neue Optimierungsverfahren für die indexierten Sequenzen, um phrase queries effizient zu beantworten. Die Performanz dieser Verfahren wird anhand von ausführlichen Experimenten auf realen Webarchiven demonstriert

    Advances in knowledge discovery and data mining Part II

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    19th Pacific-Asia Conference, PAKDD 2015, Ho Chi Minh City, Vietnam, May 19-22, 2015, Proceedings, Part II</p
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