Checkpoint duration

Checkpoint process updates the file headers of the data files and flushes the dirty buffers in cache to data files.

i) Is there any propotional relation between "number of datafiles" and time spent to perform a checkpoint ?
ii) Is the majority of the time spent to checkpoint caused by "header update"(LGWR) or "flushing dirty buffers"(DBWR) ? Received on Sun Nov 26 2006 - 18:16:40 CST