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db file scattered read官网解释：This event signifies that the user process is reading buffers into the S
Oracle Study之--Oracle等待事件（7） Free buffer waits 当一个会话将数据块从磁盘读到内存中时，它需要到内存中找到空闲的内存空间
Oracle Study之--Oracle等待事件（2）Control file parallel write当数据库中有多个控制文件的拷贝时，Oracle 需要保证信息同步地写到各个控制文件当中，这
free buffer waits官网解释： This wait event indicates that a server process was un
Oracle Study之--Oracle等待事件（3）Db file parallel read这是一个很容易引起误导的等待事件，实际上这个等待事件和并行操作（比如并行查询，并行DML）没有关系。
db file sequential read:官网解释：This event signifies that the user process is reading a buffer into the
db file parallel read官网解释： This happens during recovery. It can also happen d
buffer busy waits （热块儿争用）官网解释： This wait indicates that there are some buffer
