Endurable Transient Inconsistency in Byte-Addressable Persistent B+-Tree
- Deukyeon Hwang, Wook-Hee Kim, Y. Won, B. Nam
- Computer ScienceUSENIX Conference on File and Storage…
- 2018
Experimental results show that legacy B+-trees with FAST and FAIR schemes outperform the state-of-the-art persistent indexing structures by a large margin.
I/O Stack Optimization for Smartphones
- Sooman Jeong, Kisung Lee, Seongjin Lee, S. Son, Y. Won
- Computer ScienceUSENIX Annual Technical Conference
- 26 June 2013
This work overhauled the block I/O behavior of five filesystems under each of the five different journaling modes of SQLite, and found that the most significant inefficiency originates from the fact that filesystem journals the database journaling activity; this anomaly is referred to as the JOJ (Journaling of Journal) anomaly.
HEAPO: Heap-Based Persistent Object Store
- Taeho Hwang, Jaemin Jung, Y. Won
- Computer ScienceTOS
- 24 February 2015
A native management layer for NVRAM to eliminate redundancy between in-core and on-disk copies of the metadata, an expandable object format, a burst trie-based global name space with local name space caching, and minimal logging for undo-only crash recovery are developed.
Efficient Deduplication Techniques for Modern Backup Operation
- Jaehong Min, D. Yoon, Y. Won
- Computer ScienceIEEE transactions on computers
- 1 June 2011
This work develops prototype backup system and performed comprehensive analysis on various factors and their relationship: average chunk size, chunking speed, deduplication ratio, tablet management algorithms, and overall backup speed.
Smart layers and dumb result: IO characterization of an android-based smartphone
- Kisung Lee, Y. Won
- Computer ScienceInternational Conference on Embedded Software
- 7 October 2012
The results of this study clearly suggest that SQLite, EXT4, and the underlying NAND-based storage need to be completely overhauled and vertically integrated so as to properly and effectively incorporate their respective characteristics.
Deduplication in SSDs: Model and quantitative analysis
- Jong-Hun Kim, Choonghyun Lee, Jaehyuk Cha
- Computer ScienceIEEE Conference on Mass Storage Systems and…
- 16 April 2012
A novel deduplication framework elaborately tailored for SSDs is developed and two acceleration techniques are proposed: sampling-based filtering and recency-based fingerprint management.
Barrier-Enabled IO Stack for Flash Storage
- Y. Won, Jaemin Jung, Sangyeun Cho
- Computer ScienceUSENIX Conference on File and Storage…
- 7 November 2017
This work overhauls the IO scheduler, the dispatch module and the filesystem so that these layers are orchestrated to preserve the ordering condition imposed by the application can be delivered to the storage.
FRASH: Exploiting storage class memory in hybrid file system for hierarchical storage
- Jaemin Jung, Y. Won, Eun-ki Kim, Hyungjong Shin, Byeonggil Jeon
- Computer ScienceTOS
- 1 March 2010
A copy-on-mount technique to overcome the access latency difference between main memory and storage-class memory is developed and greatly improves the I/O performance compared to the legacy log-structured approach.
Energy-aware disk scheduling for soft real-time I/O requests
- Y. Won, Jongmin Kim, Wonmin Jung
- Computer ScienceMultimedia Systems
- 1 February 2008
This work develops an elaborate model which incorporates the energy consumption characteristics, overhead of mode transition in determining the appropriate I/O burst size and the respective disk operating schedule, and develops a prototype software with energy-aware scheduling algorithm.
NVWAL: Exploiting NVRAM in Write-Ahead Logging
- Wook-Hee Kim, Jinwoong Kim, Woongki Baek, B. Nam, Y. Won
- Computer ScienceInternational Conference on Architectural Support…
- 25 March 2016
This work develops NVWAL (NVRAM Write-Ahead Logging) for SQLite, a solution for database logs that effectively eliminates the excessive I/O overhead of filesystem-based logging or journaling and shows that application performance is much less sensitive to the NVRAM performance than the authors expected.
...
...