What is the resulting action of a checkpoint?
DBWR writes all dirty buffers in the database buffer cache to disk. • What happens when the checkpoint numbers do not match at database start up? Oracle will assume a recovery operation is necessary and generate an error. The database will not open. Each time a checkpoint is triggered, all the datafiles, control files, and redo log files are synchronized. Each file is updated with a checkpoint number. If the DBA overwrites the control file with an old copy and attempts to start up the database, it will not open because the checkpoint numbers are inconsistent. The start up will fail and recovery will be needed.
