oracle LGWR写进程 触发条件

触发LGWR写进程

1.超时(timeout)3秒
2.在Min(1M,1/3 log buffer size)时
3.提交
4.在DBWR写之前

Function of the LGWR Background Process
The log writer (LGWR) writes redo entries from the redo log buffer to the redo log files as follows:
• When the redo log buffer is one-third full
• When a timeout occurs (every three seconds)
• When there is 1 MB of redo
• Before DBWn writes modified blocks in the database buffer cache to the data files
• When a transaction commits