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dc.contributor.advisorCharles E. Leiserson and Bradley C. Kuszmaul.en_US
dc.contributor.authorNelson, Jelani (Jelani Osei)en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.en_US
dc.date.accessioned2007-04-03T17:09:55Z
dc.date.available2007-04-03T17:09:55Z
dc.date.copyright2006en_US
dc.date.issued2006en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/37084
dc.descriptionThesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.en_US
dc.descriptionIncludes bibliographical references (p. 65-68).en_US
dc.description.abstractThis thesis provides both experimental and theoretical contributions regarding external-memory dynamic search trees with fast insertions. The first contribution is the implementation of the buffered repository B-tree, a data structure that provably outperforms B-trees for updates at the cost of a constant factor decrease in query performance. This thesis also describes the cache-oblivious lookahead array, which outperforms B-trees for updates at a logarithmic cost in query performance, and does so without knowing the cache parameters of the system it is being run on. The buffered repository B-tree is an external-memory search tree that can be tuned for a tradeoff between queries and updates. Specifically, for any E [1/ lg B, 1] this data structure achieves O((1/EBl-E)(1 + logB(N/B))) block transfers for INSERT and DELETE and 0((/(1 + logB(N/B))) block transfers for SEARCH. The update complexity is amortized and is O((1/e)(1 + logB(N/B))) in the worst case. Using the value = 1/2, I was able to achieve a 17 times increase in insertion performance at the cost of only a 3 times decrease in search performance on a database with 12-byte items on a disk with a 4-kilobyte block size.en_US
dc.description.abstract(cont.) This thesis also shows how to build a cache-oblivious data structure, the cache-oblivious lookahead array, which achieves the same bounds as the buffered repository B'-tree in the case where e = 1/ lg B. Specifically, it achieves an update complexity of O((1/B) log(N/B)) and a query complexity of O(log(N/B)) block transfers. This is the first data structure to achieve these bounds cache-obliviously. The research involving the cache-oblivious lookahead array represents joint work with Michael A. Bender, Jeremy Fineman, and Bradley C. Kuszmaul.en_US
dc.description.statementofresponsibilityby Jelani Nelson.en_US
dc.format.extent68 p.en_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582
dc.subjectElectrical Engineering and Computer Science.en_US
dc.titleExternal-memory search trees with fast insertionsen_US
dc.typeThesisen_US
dc.description.degreeM.Eng.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.en_US
dc.identifier.oclc83308658en_US


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