(sorry, forgot to copy to the list) >>Looking for comments & experiences regarding sizes of datafiles. We have a >>large (6+ TB) OLTP database.... Dan you could do worse than google the oracle-l archives using search terms like 'datafiles', 'sizing', 'TB' etc; see for example: //www.freelists.org/archives/oracle-l/09-2005/msg00093.html - Choosing data file size for a multi TB database? //www.freelists.org/archives/oracle-l/11-2006/msg00626.html - Data file size - is bigger better? (I've picked messages at random - you'll need to search back and forth within these threads) Regards Nigel