• Title/Summary/Keyword: Multi-Zoned Disk

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Efficient Storage Techniques for Materialized Views Using Multi-Zoned Disks in OLAP Environment (OLAP 환경에서 다중 존 디스크를 활용한 실체뷰의 효율적 저장 기법)

  • Chang, Jae-Young
    • The Journal of Society for e-Business Studies
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    • v.14 no.1
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    • pp.143-160
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    • 2009
  • In determining the performance of OLAP database applications, the structure and the effective access methods to the underlying disk system is a significant factor. In recent years, hard disks are designed with multiple physical zones where seek times and data transfer rates vary across the zones. However, there is little consideration of multi-zone disks in previous works. Instead, they assumed a traditional disk model that comes with many simplifying assumptions such as an average seek-time and a single data transfer rate. In this paper, we propose a technique storing a set of materialized views into the multi-zoned disks in OLAP environment dealing with large sets of data. We first present the disk zoning algorithm of materialized views according to the access probabilities of each views. Also, we address the problem of storing views in the dynamic environment where data are updated continuously. Finally, through experiments, we prove the performance improvement of the proposed algorithm against the conventional methods.

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Efficient Storage Techniques for Multidimensional Index Structures in Multi-Zoned Disk Environments (다중 존 디스크 환경에서 다차원 인덱스 구조의 효율적 저장 기법)

  • Yu, Byung-Gu;Kim, Seon-Ho;Chang, Jae-Young
    • Journal of KIISE:Databases
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    • v.34 no.4
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    • pp.315-327
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    • 2007
  • The performance of database applications with large sets of multidimensional data depends on the performance of its access methods and the underlying disk system. In modeling the disk system, even though modem disks are manufactured with multiple physical zones, conventional access methods have been developed based on a traditional disk model with many simplifying assumptions. Thus, there is a marked lack of investigation on how to enhance the performance of access methods given a zoned disk model. The paper proposes novel zoning techniques that can be applied to any multidimensional access methods, both static and dynamic, enhancing the effective data transfer rate of underlying disk system by fully utilizing its zone characteristics. Our zoning techniques include data placement algorithms for multidimensional index structures and accompanying localized query processing algorithms for range queries. The experimental results show that our zoning techniques significantly improve the query performance.

Using Outermost-Zone Tracks as a Cache to Boost Disk Write Performance (디스크 쓰기 성능 향상을 위한 가장자리 영역 트랙의 이용)

  • U, Jong-Jeong;Hong, Chun-Pyo
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.11
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    • pp.3116-3123
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    • 1999
  • Current disk systems are generally designed to reduce read traffic more effectively. Hence, write traffic of the I/O workload could potentially become a bottleneck of the disk system performance. In order to overcome this problem without much cost, this paper presents using outermost-zone track of multi-zoned recording disk as a secondary disk cache. The proposed disk cache improves the disk system performance by following exploitations: speed difference between block transfer and track transfer, difference in transfer rate between outermost-zone tracks and inner tracks, reduction in the seek time caused by decreasing the number of disk cache tracks, and idle period during burst accesses. In addition, it does not waste the disk space because it allocates the caching space by the cylinder unit. The simulation results show that the proposed system improves 2.54∼3.11 times better in terms of average response time for write operations than existing disk systems..

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Mitigating the Side-effect of Starting New Session in Multimedia Streaming using Multi-zoned Disk (구역분할 디스크를 사용하는 멀티미디어 서버에서 새로운 세션 시작에 따른 스케줄링 지연 현상의 최소화)

  • Cho, Kyeong-Sun;Won, You-Jip;Shin, Il-Hoon;Koh, Kern
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.8
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    • pp.445-452
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    • 2004
  • Zoning technology of disk improved the performance of disk subsystem with increase of storage capacity and average transfer bandwidth. SCAN disk scheduling with double buffering is used to utilize the performance of zoned disk in multimedia system. However, this method has a problem that generates jitter when the number of steams increases. In this article, we propose the novel approach, pre-buffering policy, to overcome this problem. Pre-buffering avoids jitter by buffering the lack of data before starting service, which is estimated from the current cycle length and the maximum cycle length. We can calculate cycle length, data sire needed in each cycle and the possible lack of data caused by the increase of the number of streams using the numerical model of disk subsystem. Pre-buffering can be applied for multimedia systems and contribute to provide clients with high quality service without jitter.