1.
The Total size of the log buffer is determined by LOG_BUFFER parameter.
2.
Only Server process may pin a data block in exclusive mode.
3.
LGWR writes to the redo log files when:
- The redo log buffer is 1/3 full.
- 1 MB of data have been written to the redo log buffer.
- A 3-second time-out occurs.
- commit!
- before dbwr write out dirty buffers
- A thread is closed
- Acquire the redo writing and redo allocation latches
- determine the buffer to write out
- Release the redo allocation latch
- determine how many writes are required
- Log file parallel write
- Log buffer space
- Log file sync
- REDO writes
本文转自maclean_007 51CTO博客,原文链接:http://blog.51cto.com/maclean/1276776