Re: switch logfile, checkpoint, active and inactive logfile

>
> returns control to you after the logfile is switched, which does not
> necessarily mean that it will complete the checkpoint by then. It is quite
> possible that the checkpoint completes some time after the switch or perhaps
> does not complete at all.

According to Oracle8i Concepts:

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.

Now I got other questions:
1) switch logfile DOES trigger the checkpoint instaneously, but the checkpoint

   may not be finished. So now when the headers of control files and datafiles

   are updated? after DBWn have done job or checkpoint is initiated?

2) If LGWR jumps to the next logfile (now becomes current) without waiting for

   Checkpoint to be done, the checkpoint for instance recovery is in the

   current logfile, or previous, but still active logfile?

3) Instance recovery roll forward to the latest checkpoint, so when this point

   of check point is marked? in the begining of checkpoint or the end?        

Thanks for the reply. Until this point (not checkpoint) I feel the difficulty
of Oracle. Received on Thu Apr 24 2003 - 21:31:04 CEST