On multidimensional data and modern disks
On multidimensional data and modern disks
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在多维数据和现代磁盘上
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
G. Ganger
中科院分区：
文献类型：
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作者：
S. Schlosser;J. Schindler;Stratos Papadomanolakis;Minglong Shao;A. Ailamaki;C. Faloutsos;G. Ganger
由于磁盘只能有效地访问一维数据这一根深蒂固的概念，当前用于将多维数据映射到磁盘块的方法要么只允许在一个维度上的有效访问，权衡其他维度上的访问效率，要么同等地惩罚对所有维度的访问。然而，现有的技术和功能容易在磁盘固件内可用，可以识别非连续的逻辑块，保持多维数据集的空间局部性。这些块跨越大约一百个相邻轨道，可以以最小的定位成本访问。本文详细介绍了这些技术，分析了它们的趋势，并展示了如何在保持现有抽象的同时将它们公开给应用程序。所描述的方法可以实现由盘技术提供的最佳可能的访问效率：沿主维度沿着顺序访问和以最小定位成本访问所有其他维度。一个原型实现的实验评估表明，减少整体的I/O时间的多维数据查询的30%和50%相比，现有的方法。
With the deeply-ingrained notion that disks can efficiently access only one dimensional data, current approaches for mapping multidimensional data to disk blocks either allow efficient accesses in only one dimension, trading off the efficiency of accesses in other dimensions, or equally penalize access to all dimensions. Yet, existing technology and functions readily available inside disk firmware can identify non-contiguous logical blocks that preserve spatial locality of multidimensional datasets. These blocks, which span on the order of a hundred adjacent tracks, can be accessed with minimal positioning cost. This paper details these technologies, analyzes their trends, and shows how they can be exposed to applications while maintaining existing abstractions. The described approach can achieve the best possible access efficiency afforded by the disk technologies: sequential access along primary dimension and access with minimal positioning cost for all other dimensions. Experimental evaluation of a prototype implementation demonstrates a reduction of overall I/O time for multi-dimensional data queries between 30% and 50% when compared to existing approaches.