Tree Indexing on Flash Disks

Abstract-- Large flash disks have become an attractive alternative to magnetic hard disks, due to their high random read performance, low energy consumption and other features. However, writes, especially random writes, on the flash disk are inherently much slower than reads because of the erase-beforewrite mechanism. To address this asymmetry of read-write speeds in indexing on the flash disk, we propose the FD-tree, a tree index designed with the logarithmic method and fractional cascading techniques. With the logarithmic method, an FD-tree consists of the head tree ? a small B+-tree on the top, and a few levels of sorted runs of increasing sizes at the bottom. This design is write-optimized for the flash disk; in particular, an index search will potentially go through more levels or visit more nodes, but random writes are limited to the head tree, and are subsequently transformed into sequential ones through merging into the lower runs. With the fractional cascading technique, we st...

• Type: Conference
• Year: 2009
• Where: ICDE
• Authors: Yinan Li, Bingsheng He, Qiong Luo, Ke Yi
• Keywords: Database, Flash Disk, Fractional Cascading Technique, Fractional Cascading Techniques, ICDE 2009, Large Flash Disks, Random Writes