Flash-Optimized B＋-Tree

• Published in: Journal of computer science and technology Vol. 25; no. 3; pp. 509 - 522
• Main Author: 安世通 胡海波 李宇 徐建良
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2010; Springer Nature B.V; Department of Computer Science,Hong Kong Baptist University,Kowloon Tong,Hong Kong,China
• Subjects: Algorithms; Artificial Intelligence; Asymmetry; Buffers; Computer Science; Computer simulation; Data Structures and Information Theory; Design; Deterioration; Flash memory (computers); Hard disks; Indexing; Information Systems Applications (incl.Internet); Policies; Sanitation services; Segments; Software Engineering; Theory of Computation; 仿真结果; 快闪记忆体; 技术能力; 查询效率; 索引方法; 选择问题; 闪存器件; flash memory; indexing; B+-tree; lazy update
• ISSN: 1000-9000; 1860-4749
• DOI: 10.1007/s11390-010-9341-1

With the rapid increasing capacity of flash memory, flash-aware indexing techniques are highly desirable for flash devices. The unique features of flash memory, such as the erase-before-write constraint and the asymmetric read/write cost, severely deteriorate the performance of the traditional B＋-tree algorithm. In this paper, we propose an optimized indexing method, called lazy-update B＋-tree, to overcome the limitations of flash memory. The basic idea is to defer the committing of update requests to the B~-tree by buffering them in a segment of main memory. They are later committed in groups so that the cost of each write operation can be amortized by a bunch of update requests. We identify a victim selection problem for the lazy-update B＋-tree and develop two heuristic-based commit policies to address this problem. Simulation results show that the proposed lazy-update method, along with a well-designed commit policy, greatly improves the update performance of the traditional B＋-tree while preserving the query efficiency.