Boosting Dual Range Query Efficiency for PCM-based Multiversion Index Design

• Main Authors: Wang, I-Ju, 王乙如
• Other Authors: Shih, Wei-Kuan
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/xbjd3a

碩士 === 國立清華大學 === 資訊工程學系所 === 106 === In this paper, we present a novel index structure called the hybrid index structure, which is suitable for indexing the embedded multiversion databases using NVM storage as a medium. Embedded database systems are popularly applyed in various kinds of systems, e.g., cyber-physical systems (CPS). For the requirement of accessing the historical data, a multiversion index is introduced to maintain multiple versions of data items in an effective way. However, the structrural maintainance problem is a complex issue for the designer both because the space and time utilization. 　　In previous work, the multiversion B-tree (MVBT) [1] has already provided an efficient indexing structure for indexing multiversion data items in an embedded multiversion databases and the structure of MVBT is not that difficult to maintain. Besides, it also bring out a good response of version-range query. However, the MVBT indexing structure may lead to a large waste of space due to the frequent version/key split. As the consequence, the space-efficient multiversion index (SEMI) [2] have proposed to solve this problem. Although SEMI has a brilliant space-efficiency on multiversion indexing structure, but the structure of it is oppositely hard to maintain. Furthermore, it may occur thrashing when the key is getting larger. Therefore, in our approach, we proposed an hybrid index structure for both of the efficiency of space and time complexity, by cut down the amount of redundant data.