External-memory search trees with fast insertions

This 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.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Nelson, Jelani (Jelani Osei)

Advisor dc:contributor.advisor

• Charles E. Leiserson and Bradley C. Kuszmaul.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.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.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/37084

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/37084