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67
STXXL: Standard template library for XXL data sets
 In: Proc. of ESA 2005. Volume 3669 of LNCS
, 2005
"... for processing huge data sets that can fit only on hard disks. It supports parallel disks, overlapping between disk I/O and computation and it is the first I/Oefficient algorithm library that supports the pipelining technique that can save more than half of the I/Os. STXXL has been applied both in ..."
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Cited by 50 (5 self)
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for processing huge data sets that can fit only on hard disks. It supports parallel disks, overlapping between disk I/O and computation and it is the first I/Oefficient algorithm library that supports the pipelining technique that can save more than half of the I/Os. STXXL has been applied both in academic and industrial environments for a range of problems including text processing, graph algorithms, computational geometry, gaussian elimination, visualization, and analysis of microscopic images, differential cryptographic analysis, etc. The performance of STXXL and its applications is evaluated on synthetic and realworld inputs. We present the design of the library, how its performance features are supported, and demonstrate how the library integrates with STL. KEY WORDS: very large data sets; software library; C++ standard template library; algorithm engineering 1.
Cache oblivious distribution sweeping
 IN PROC. 29TH INTERNATIONAL COLLOQUIUM ON AUTOMATA, LANGUAGES, AND PROGRAMMING (ICALP), VOLUME 2380 OF LNCS
, 2002
"... We adapt the distribution sweeping method to the cache oblivious model. Distribution sweeping is the name used for a general approach for divideandconquer algorithms where the combination of solved subproblems can be viewed as a merging process of streams. We demonstrate by a series of algorithms ..."
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Cited by 42 (10 self)
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We adapt the distribution sweeping method to the cache oblivious model. Distribution sweeping is the name used for a general approach for divideandconquer algorithms where the combination of solved subproblems can be viewed as a merging process of streams. We demonstrate by a series of algorithms for specific problems the feasibility of the method in a cache oblivious setting. The problems all come from computational geometry, and are: orthogonal line segment intersection reporting, the all nearest neighbors problem, the 3D maxima problem, computing the measure of a set of axisparallel rectangles, computing the visibility of a set of line segments from a point, batched orthogonal range queries, and reporting pairwise intersections of axisparallel rectangles. Our basic building block is a simplified version of the cache oblivious sorting algorithm Funnelsort of Frigo et al., which is of independent interest.
Cacheoblivious algorithms and data structures
 IN LECTURE NOTES FROM THE EEF SUMMER SCHOOL ON MASSIVE DATA SETS
, 2002
"... A recent direction in the design of cacheefficient and diskefficient algorithms and data structures is the notion of cache obliviousness, introduced by Frigo, Leiserson, Prokop, and Ramachandran in 1999. Cacheoblivious algorithms perform well on a multilevel memory hierarchy without knowing any pa ..."
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Cited by 40 (2 self)
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A recent direction in the design of cacheefficient and diskefficient algorithms and data structures is the notion of cache obliviousness, introduced by Frigo, Leiserson, Prokop, and Ramachandran in 1999. Cacheoblivious algorithms perform well on a multilevel memory hierarchy without knowing any parameters of the hierarchy, only knowing the existence of a hierarchy. Equivalently, a single cacheoblivious algorithm is efficient on all memory hierarchies simultaneously. While such results might seem impossible, a recent body of work has developed cacheoblivious algorithms and data structures that perform as well or nearly as well as standard externalmemory structures which require knowledge of the cache/memory size and block transfer size. Here we describe several of these results with the intent of elucidating the techniques behind their design. Perhaps the most exciting of these results are the data structures, which form general building blocks immediately
On the limits of cacheobliviousness
 IN PROC. 35TH ANNUAL ACM SYMPOSIUM ON THEORY OF COMPUTING
, 2003
"... In this paper, we present lower bounds for permuting and sorting in the cacheoblivious model. We prove that (1) I/O optimal cacheoblivious comparison based sorting is not possible without a tall cache assumption, and (2) there does not exist an I/O optimalcacheoblivious algorithm for permuting, ..."
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Cited by 38 (6 self)
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In this paper, we present lower bounds for permuting and sorting in the cacheoblivious model. We prove that (1) I/O optimal cacheoblivious comparison based sorting is not possible without a tall cache assumption, and (2) there does not exist an I/O optimalcacheoblivious algorithm for permuting, not even in the presence of a tall cache assumption.Our results for sorting show the existence of an inherent tradeoff in the cacheoblivious model between the strength of the tall cache assumption and the overhead for the case M >> B, and show that Funnelsort and recursive binary mergesort are optimal algorithms in the sense that they attain this tradeoff.
Funnel heap  a cache oblivious priority queue
 In Proc. 13th Annual International Symposium on Algorithms and Computation, volume 2518 of LNCS
, 2002
"... Abstract The cache oblivious model of computation is a twolevel memory model with the assumption that the parameters of the model are unknown to the algorithms. A consequence of this assumption is that an algorithm efficient in the cache oblivious model is automatically efficient in a multilevel m ..."
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Cited by 35 (6 self)
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Abstract The cache oblivious model of computation is a twolevel memory model with the assumption that the parameters of the model are unknown to the algorithms. A consequence of this assumption is that an algorithm efficient in the cache oblivious model is automatically efficient in a multilevel memory model. Arge et al. recently presented the first optimal cache oblivious priority queue, and demonstrated the importance of this result by providing the first cache oblivious algorithms for graph problems. Their structure uses cache oblivious sorting and selection as subroutines. In this paper, we devise an alternative optimal cache oblivious priority queue based only on binary merging. We also show that our structure can be made adaptive to different usage profiles. 1
Engineering a cacheoblivious sorting algorithm
 IN PROC. 6TH WORKSHOP ON ALGORITHM ENGINEERING AND EXPERIMENTS
, 2004
"... The cacheoblivious model of computation is a twolevel memory model with the assumption that the parameters of the model are unknown to the algorithms. A consequence of this assumption is that an algorithm efficient in the cache oblivious model is automatically efficient in a multilevel memory mod ..."
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Cited by 29 (1 self)
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The cacheoblivious model of computation is a twolevel memory model with the assumption that the parameters of the model are unknown to the algorithms. A consequence of this assumption is that an algorithm efficient in the cache oblivious model is automatically efficient in a multilevel memory model. Since the introduction of the cacheoblivious model by Frigo et al. in 1999, a number of algorithms and data structures in the model has been proposed and analyzed. However, less attention has been given to whether the nice theoretical proporities of cacheoblivious algorithms carry over into practice. This paper is an algorithmic engineering study of cacheoblivious sorting. We investigate a number of implementation issues and parameters choices for the cacheoblivious sorting algorithm Lazy Funnelsort by empirical methods, and compare the final algorithm with Quicksort, the established standard for comparison based sorting, as well as with recent cacheaware proposals. The main result is a carefully implemented cacheoblivious sorting algorithm, which we compare to the best implementation of Quicksort we can find, and find that it competes very well for input residing in RAM, and outperforms Quicksort for input on disk.
CacheOblivious Streaming Btrees
, 2007
"... A streaming Btree is a dictionary that efficiently implements insertions and range queries. We present two cacheoblivious streaming Btrees, the shuttle tree, and the cacheoblivious lookahead array (COLA). For blocktransfer size B and on N elements, the shuttle tree implements searches in optima ..."
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Cited by 28 (9 self)
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A streaming Btree is a dictionary that efficiently implements insertions and range queries. We present two cacheoblivious streaming Btrees, the shuttle tree, and the cacheoblivious lookahead array (COLA). For blocktransfer size B and on N elements, the shuttle tree implements searches in optimal O ` logB+1 N ´ transfers, range queries of L successive elements in optimal O ` logB+1 N + L/B ´ transfers, and insertions in O “ (logB+1 N)/BΘ(1/(loglogB)2 ”) +(log2 N)/B transfers, which is an asymptotic speedup over traditional Btrees if B ≥ (logN) 1+c/logloglog2 N for any constant c> 1. A COLA implements searches in O(logN) transfers, range queries in O(logN + L/B) transfers, and insertions in amortized O((logN)/B) transfers, matching the bounds for a (cacheaware) buffered repository tree. A partially deamortized COLA matches these bounds but reduces the worstcase insertion cost to O(logN) if memory size M = Ω(logN). We also present a cacheaware version of the COLA, the lookahead array, which achieves the same bounds as Brodal and Fagerberg’s (cacheaware) Bεtree. We compare our COLA implementation to a traditional Btree. Our COLA implementation runs 790 times faster for random insertions, 3.1 times slower for insertions of sorted data, and 3.5 times slower for searches.
Scanning and traversing: maintaining data for traversals in a memory hierarchy
 In Proceedings of the 10th Annual European Symposium on Algorithms
, 2002
"... Abstract. We study the problem of maintaining a dynamic ordered set subject to insertions, deletions, and traversals of k consecutive elements. This problem is trivially solved on a RAM and on a simple twolevel memory hierarchy. We explore this traversal problem on more realistic memory models: the ..."
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Cited by 27 (11 self)
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Abstract. We study the problem of maintaining a dynamic ordered set subject to insertions, deletions, and traversals of k consecutive elements. This problem is trivially solved on a RAM and on a simple twolevel memory hierarchy. We explore this traversal problem on more realistic memory models: the cacheoblivious model, which applies to unknown and multilevel memory hierarchies, and sequentialaccess models, where sequential block transfers are less expensive than random block transfers. 1
CacheOblivious Data Structures and Algorithms for Undirected BreadthFirst Search and Shortest Paths
 IN PROCEEDINGS OF THE 9TH SCANDINAVIAN WORKSHOP ON ALGORITHM THEORY
, 2004
"... We present improved cacheoblivious data structures and algorithms for breadthfirst search and the singlesource shortest path problem on undirected graphs with nonnegative edge weights. Our results close the performance gap between the currently best cacheaware algorithms for these problems and ..."
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Cited by 26 (10 self)
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We present improved cacheoblivious data structures and algorithms for breadthfirst search and the singlesource shortest path problem on undirected graphs with nonnegative edge weights. Our results close the performance gap between the currently best cacheaware algorithms for these problems and their cacheoblivious counterparts. Our shortestpath algorithm relies on a new data structure, called bucket heap, which is the first cacheoblivious priority queue to efficiently support a weak DecreaseKey operation.