物件導向資料庫系統中緩衝區的設計與實作

Abstract

由於複雜物件的普遍應用,物件導向資料庫與傳統關聯式資料庫的使用 在型態上有很明顯的不同.為了有較好的效率,在一個對等式的物件導向資 料庫CACTUS中找出適合它的緩衝區管理方法是必須的.在本篇論文中我們 綜合了資料頁最近的參用情形與參用的頻率提出一個新的方法,並且與之 前人們提出的兩種方法,實作在我們實驗室的物件導向資料庫系統中.另外 根據物件導向資料庫的測試平台-OO7進行測試.根據實驗可以知道對於物 件導向資料庫系統而言,緩衝區管理員的設計不但需要注意到緩衝區的命 中率,同時也要留意緩衝區置換方法的複雜度. As the general use of complex objects in object oriented database system, the using types of OODB are different from traditional relational database system. For the better performance purpose, we have to find a better buffer replacement policy in CACTUS.In this thesis, we implement a new buffer replacement policy. This policy combines the recently reference condition of data pages and the reference frequency of data pages. We also implement two other buffer replacement policies in CACTUS. Finally, according to object oriented benchmark-OO7, we do performance evaluation and analyze the three buffer replacement policies. In the experiments which we do in this thesis, we know some issues to buffer manager in CACTUS. We must not only pay attention to the hit ratio of buffer pool, but also care the complexity of buffer manager.