中文摘要：

随着关系型数据库概念的提出，越来越多的关系型数据库管理系统（RDBMS）也先后出现，而存储系统是整个DBMS的基础，其性能的好坏决定着数据库整体的优劣。针对这一情况，分析了开源数据库PostgreSQL的存储系统模块。存储系统涉及很多关键技术，而缓冲区正是整个存储系统模块的核心部分，重点阐述了PostgreSQL缓冲区管理子模块内部的组织架构与实现机制，在PostgreSQL8．4．2缓冲区部分源码的基础上提出结论。结论指出了缓冲区管理模块的实现机制，并通过对比分析了其内部本地缓冲区和共享缓冲区的优劣。

英文摘要：

With the proposed concept of relational database, a growing number of relational database management system （RDBMS ） have also appeared. The storage system is the base of whole DBMS,and the storage systems performance determines the overall merits of the database. According to such situation, analyse the open source PostgreSQL database storage system module, storage system is involved in many key technologies,the buffer storage system module is the core. It focuses on PostgreSQL buffer management sub-module＇s organization and implementation mechanisms, makes the conclusion based on the PostgreSQL 8.4.2 source code, it points out management modules implementation mechanism, and analyse the fit or unfit of its local buffer and share buffer.