Re: Checkpoint - v$datafile_header

ashok_jayaraman_at_yahoo.com (Jayaraman Ashok) wrote in message > To find out how frequent the checkpoints occur, i queried the
> v$datafile_header for the checkpoint_time. It tallied with the last
> log switch time. But after the next log switch had occurred , the
> v$datafile_header still shows only the last value. Even after 25
> minutes of the log switch, the view has not been refreshed.When is it
> updated?

Maybe because there's nothing to checkpoint. I.e. there're no dirty block buffers. Try a DML and commit followed by switch logfile and check checkpoint_time.

 Also what is the checkpoint_count column and what does it
> signify? IS it the number of changes that has occurred on each
> datafile or is it something else? The value is different for different
> datafiles and is the maximum on system datafile. Please share your
> views and knowledge.

Checkpoint_count counts the number of checkpoints performed on this datafile since its creation. Since system datafiles have existed since the database creation time, they should have the highest number (possibly the same with your rollback segment datafiles).

Yong Huang Received on Mon Aug 12 2002 - 14:22:02 CDT