SQL & PL/SQL

Folks,

Working on Oracle 11g, the problem that I have detailed below appears to show my MV is not refreshing, I am not sure why, maybe I missed a step, any hints much appreciated:-

SQL> create table t
  2  (
  3    col1 varchar2(10)
  4  );
 
Table created.
 
SQL>
SQL> alter table t add constraint pk_col1 primary key (COL1);
 
Table altered.
 
SQL> insert into t select object_name from all_objects where rownum < 6;
 
5 rows created.
 
SQL> commit;
 
Commit complete.
 
SQL> select * from t;
 
COL1
----------
ICOL$
I_USER1
CON$
UNDO$
C_COBJ#
 
SQL> create materialized view log on t with primary key;
 
Materialized view log created.
 
SQL> create materialized view mv
  2  refresh fast on demand
  3  start with sysdate next trunc(sysdate,'mi') + 1/24/12
  4  as
  5  select col1 from t;
 
Materialized view created.
 
SQL> select * from mv;
 
COL1
----------
ICOL$
I_USER1
CON$
UNDO$
C_COBJ#
 
SQL> alter table t add col2 varchar2(20);
 
Table altered.
 
SQL> update t set col2 = 'hello';
 
5 rows updated.
 
SQL> commit
  2  ;
 
Commit complete.
 
SQL> select col1,col2 from t;
 
COL1       COL2
---------- --------------------
ICOL$      hello
I_USER1    hello
CON$       hello
UNDO$      hello
C_COBJ#    hello
SQL> select * from mv;
 
SQL> alter  materialized view mv add col2 varchar2(20);
 
Materialized view altered.
 
SQL> select * from mv;
 
COL1       COL2
---------- --------------------
ICOL$
I_USER1
CON$
UNDO$
C_COBJ#
 
SQL> EXEC DBMS_MVIEW.REFRESH('MV');
 
PL/SQL procedure successfully completed.
 
SQL> select * from mv;
 
COL1       COL2
---------- --------------------
ICOL$
I_USER1
CON$
UNDO$
C_COBJ#