i suspect the problem lies in selecting from the view in the mat view definition. i had trouble getting query re-write to happen when doing something similar. ended up copying the select statement from the view into the definition of the mat view and all was fine. this was 9.2.0.6. in my case, i always planned to do complete refresh anyway so the fast refresh issue didn't bother me. but i do recall the fine manuals were short on details. fwiw - ran your test case on my 9.2.0.6 slowaris instance and got exact same results. > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of jaromir nemec > Sent: Friday, May 12, 2006 9:39 AM > To: oracle-l@xxxxxxxxxxxxx > Subject: fast refresh of MV based on a view > > > Hi, > > I try to define a MV based on a (very simple) view. > ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ -- //www.freelists.org/webpage/oracle-l