Lazy-Update B+-Tree for Flash Devices

— With the rapid increasing capacity of flash chips, 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 a new indexing method, called lazy-update B+-tree, to overcome the limitations of flash memory. The basic idea is to defer the time of committing update requests to the B+-tree by buffering them in a segment of main memory. They are later committed in groups so that 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 the problem. Simulation results show that the proposed lazyupdate method, along with a well-designed commit policy, greatly improves the update performance of the traditional B+-tree while pr...

• Type: Conference
• Year: 2009
• Where: MDM
• Authors: Sai Tung On, Haibo Hu, Yu Li, Jianliang Xu
• Keywords: Communications, MDM 2009, Traditional B+-tree, Update Requests, flash Memory