多磁碟資料庫系統檔案配置最佳化模式

Abstract

本文發展一在多磁碟資料庫系統下的檔案配置最佳化模式，以縮短磁碟輸 出輸入的時間，俾增進資料庫系統運作的效能。本文以Rotem的檔案配置 模式[2]為參考，發展一計算優點更佳的模式。Rotem的模式運用在M個磁 碟有N個關聯表的多磁碟資料配置的問題上時，須使用N((N-1)/2+N+M( N-1)/2)個0-1變數來解題。本文提出的修正模式以與Rotem模式作比較如 下：第一個修正模式須NM個0-1變數及N(N-1)(M+1)/2個連續變數第二個修 正模式只須NM個0-1變數及N(N-1)/2個連續變數測試結果發現修正模式的 計算效率均比Rotem模式為佳，尤以第二個修正模式之效率為最好。 This paper approaches optimal file allocation in a single processor/multidisk database system, such that allocation can increase I/O throughput. We introduce the optimal method which involves N((N-1)/2+M+M(N-1)/2) 0-1 variables for the multidisk allocation problem with N relations and M disks from Rotem et al.(1993)[2]. This thesis proposes both modified models which compare with Rotem's model as following: First modified model contains NM 0-1 variables and N(N-1)(M+1)/2 continuous variables.Second modified model contains NM 0-1 variables and N( N-1)/2 continuous variables.The results show that both modified models are more computationally effective. Especially, the second modified model is the most powerful.