ocp认真考试指南第一章
数据库存储结构： 物理数据库存储结构： 必须的三类文件： 控制文件(controlFile):multiplexing the controfile 多路复用控制文件,指向其他重要文件，存储序列号和时间戳 联机重做日志文件(redo log):联机重做日志文件盒归档日志文件.最低有2个组，每个组至
数据库存储结构：
物理数据库存储结构：
必须的三类文件：
控制文件(controlFile):multiplexing the controfile 多路复用控制文件,指向其他重要文件，存储序列号和时间戳
联机重做日志文件(redo log):联机重做日志文件盒归档日志文件.最低有2个组，每个组至少有2个成员,第一个组写完后，将第一个进行归档，开始写第二个，这么循环下去.不停机下可以对重做日志文件进行移动,添加,删除操作.
数据文件(datafile):至少创建两个数据文件(SYSTEM表空间(存储数据字典)和SYSAUX表空间(存储数据字典辅助数据)).逻辑上讲,它们为段的存储库.服务器进程对数据文件执行读操作，而DBWn对数据文件执行写操作.
外部文件:初始化参数文件,口令文件,归档重做日志文件,日志和跟踪文件
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