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Efficient external memory structures for range-aggregate queries

Agarwal, Pankaj K and Arge, Lars and Govindarajan, Sathish and Yang, Jun and Yi, Ke (2013) Efficient external memory structures for range-aggregate queries. In: COMPUTATIONAL GEOMETRY-THEORY AND APPLICATIONS, 46 (3). pp. 358-370.

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Official URL: http://dx.doi.org/10.1016/j.comgeo.2012.10.003


We present external memory data structures for efficiently answering range-aggregate queries. The range-aggregate problem is defined as follows: Given a set of weighted points in R-d, compute the aggregate of the weights of the points that lie inside a d-dimensional orthogonal query rectangle. The aggregates we consider in this paper include COUNT, sum, and MAX. First, we develop a structure for answering two-dimensional range-COUNT queries that uses O(N/B) disk blocks and answers a query in O(log(B) N) I/Os, where N is the number of input points and B is the disk block size. The structure can be extended to obtain a near-linear-size structure for answering range-sum queries using O(log(B) N) I/Os, and a linear-size structure for answering range-MAX queries in O(log(B)(2) N) I/Os. Our structures can be made dynamic and extended to higher dimensions. (C) 2012 Elsevier B.V. All rights reserved.

Item Type: Journal Article
Additional Information: Copyright for this article belongs to ELSEVIER SCIENCE BV, NETHERLANDS
Keywords: External memory algorithms;Range-aggregation;Data structures
Department/Centre: Division of Electrical Sciences > Computer Science & Automation
Date Deposited: 25 Jan 2013 12:42
Last Modified: 25 Jan 2013 12:42
URI: http://eprints.iisc.ac.in/id/eprint/45650

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