Test1:
evntid        date
11            12-jan-2000
11            null
11            13-dec-2008
------------------------------------
12            10-jan-2010
12            30-nov-2014
12            20-feb-2013

Requirement is  Creation of Fast refresh MView with the following capabilities.
if u execute it like the following statement:
Select DECODE (COUNT(EVNTID),COUNT(DATE1),MAX(DATE1),NULL) FROM  TEST1 WHERE EVNTID=12 ;
it should return the value: 30-nov-2014

Select DECODE (COUNT(EVNTID),COUNT(DATE1),MAX(DATE1),NULL) FROM  TEST1 WHERE EVNTID=11;
it should return the value :     (null)

But for us the problem is The mview will not accept the analytic functions usage in Fast refresh Mview.