CKPT PROCESS

[dbstudent]

Hello,

Can someone please explain to me what the checkpoint process does. I am not clear whether it writes directly to the datafile headers directly or does it pass on the scn number to the DBWn?

dbstudent

 

[dbtoo2001]

http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96521/manproc.htm#15002

Checkpoint (CKPT)
At specific times, all modified database buffers in the system global area are written to the datafiles by DBWn. This event is called a checkpoint. The checkpoint process is responsible for signalling DBWn at checkpoints and updating all the datafiles and control files of the database to indicate the most recent checkpoint.



Checkpoint (CKPT)
At specific times, all modified database buffers in the SGA are written to the datafiles by DBWn. This event is called a checkpoint. The checkpoint process is responsible for signaling DBWn at checkpoints and updating all the datafiles and control files of the database to indicate the most recent checkpoint.


Checkpoint Process (CKPT)
When a checkpoint occurs, Oracle must update the headers of all datafiles to record the details of the checkpoint. This is done by the CKPT process. The CKPT process does not write blocks to disk; DBWn always performs that work.

The statistic DBWR checkpoints displayed by the System_Statistics monitor in Enterprise Manager indicates the number of checkpoint requests completed.