hashinaflashhashtablesforsolidstatedevices-資料下載頁(yè)
2025-09-20 21:04本頁(yè)面
【導(dǎo)讀】Tatikonda?CharuAggarwal?Scientificdata,Twitter,Facebook,Lackmovingparts. FasterRandomAccess. Lowerenergyusage. LimitedLifetime. Batchupdates. (A.Anand’10),(D.Andersen’09),(B.Device.Batchupdates
【正文】 segment, the average query time only reduces by fractions of a second. This suggest the majority of the query time is incurred by the disk. 11/30/2020 22 Results (AVERAGE Query Time) By varying the on disk buffer, as a percentage of the data segment, the average query time decreases substantiall for MDBL This reduction is seen in both datasets. MDB requires block reads in the CS. 11/30/2020 23 Results (AVERAGE Query Time) Using the Wiki dataset, we pared SLC with MLC We experience consistent performance 11/30/2020 24 Results(AVERAGE I/O) In this experiment, we set the in memory buffer to 5% and the CS to % of the primary hash table size Simulation time is highest for MB because of the block erasures (next slide). MDBL is faster than MDB because of the increased page level operations 25 Results(Cleans/Erasures) Cleans are extremely low for both MDB and MDBL relative to MB This is caused by the page level sequential operations Queries are effected by cleans because the SSD must allocate resources to cleaning moving 11/30/2020 26 Discussion and Conclusion ? Flash Devices are gaining popularity ? Low Latency, High Random Read Performance, Low Energy ? Limited lifetime, poor random write performance ? Hash tables are useful data structures in many data mining and IR algorithms ? They exhibit random write patterns ?Challenging for Flash Devices ? We have demonstrated that a proper Hash table for Flash Devices will have ? Inmemory buffer for batch memory?disk updates ? On disk data buffer with page level operations 11/30/2020 27 Future work ? Our current designs rely on hash functions that use the mod operator ?Extendible Hashing ? Checkpoint methods for crash recovery ? Examine on Real SSD ?Disksim is great for fiuning and examining statistics 11/30/2020 28 Questions?
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1