Checkpoints help to reduce the time required for instance recovery.It do following things:
1. A checkpoint is an event that flushes the modified data from the buffer cache to the disk and updates the control file and data files.
2.The checkpoint process (CKPT) updates the headers of data files and control files; the actual blocks
are written to the file by the DBWn process.
3.beforeDBRn process,the LGWR write log buffer to log files.
So from the above, you can see the difference between them, the CKPT updates the heads of data files and control files and DBRndon't.
Learn to speak the correct language. What do you think a DBWR is? It's a background process, not the action of writing.
BTW, ever since Oracle started to support multiple DB Writers, it's slightly better to say DBWn than DBWR to refer to the DB Writers in general, even better if you could use italic font for "n" after "DBW".
Yong Huang 最初由 33281 发布
[B]CKPT触发的DBWR与正常的DBWR没有区别吗？
好象还有个fast_start_io_target参数控制。 [/B]
