TY - JOUR

T1 - Efficient bundle sorting

AU - Matias, Yossi

AU - Segal, Eran

AU - Vitter, Jeffrey Scott

PY - 2006

Y1 - 2006

N2 - Many data sets to be sorted consist of a limited number of distinct keys. Sorting such data sets can be thought of as bundling together identical keys and having the bundles placed in order; we therefore denote this as bundle sorting, We describe an efficient algorithm for bundle sorting in external memory, which requires at most c(N/B) logM/B k disk accesses, where N is the number of keys, M is the size of internal memory, k is the number of distinct keys, ⊖ is the transfer block size, and 2 < c < 4. For moderately sized k, this bound circumvents the ⊖((N/B)logM/B(N/B)) I/O lower bound known for general sorting. We show that our algorithm is optimal by proving a matching lower bound for bundle sorting. The improved running time of bundle sorting over general sorting can be significant in practice, as demonstrated by experimentation. An important feature of the new algorithm is that it is executed "in-place," requiring no additional disk space.

AB - Many data sets to be sorted consist of a limited number of distinct keys. Sorting such data sets can be thought of as bundling together identical keys and having the bundles placed in order; we therefore denote this as bundle sorting, We describe an efficient algorithm for bundle sorting in external memory, which requires at most c(N/B) logM/B k disk accesses, where N is the number of keys, M is the size of internal memory, k is the number of distinct keys, ⊖ is the transfer block size, and 2 < c < 4. For moderately sized k, this bound circumvents the ⊖((N/B)logM/B(N/B)) I/O lower bound known for general sorting. We show that our algorithm is optimal by proving a matching lower bound for bundle sorting. The improved running time of bundle sorting over general sorting can be significant in practice, as demonstrated by experimentation. An important feature of the new algorithm is that it is executed "in-place," requiring no additional disk space.

KW - Algorithms

KW - Bundle sorting

KW - External memory

KW - Sorting

UR - http://www.scopus.com/inward/record.url?scp=34247242213&partnerID=8YFLogxK

U2 - 10.1137/S0097539704446554

DO - 10.1137/S0097539704446554

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AN - SCOPUS:34247242213

SN - 0097-5397

VL - 36

SP - 394

EP - 410

JO - SIAM Journal on Computing

JF - SIAM Journal on Computing

IS - 2

ER -