oracle lgwr如何写redolog
例如一个实例只有一个redo thread,即一个LGWR，对吧？
但是一个日志组，假设里面有3个日志成员，那么一个LGWR如何同时向3个日志成员写呢？
明显做不到啊？在一个时间段内，一个thread只能写一个日志成员吧？
from：Yong Huang
log file headers are written sequentially (wait event: log file single write). Log file bodies are written in parallel (event: log file parallel wrioracle账号te). As guoyJoe said, OS level async write can handle it.
日志文件头连续写的，日志文件的内容是并行写的，主要是通过 os 的异步i/o来实现的。