Partition/Subpartition by hash

Question

create table demo_table (
ID number(9) primary key,
Col1 varchar2(10) not null,
Col2 varchar2(10) not null,
Col3 varchar2(10)
partition by hash(col1)
subpartition by hash (col2)
partitions 4 subpartitions 4;
Now I would expect there to be a total of 16 sub-partitions. However I only get seven. How do I tell it to do all four partitions with 4 subpartitions instead of just the first one?
select * from user_segments where segment_name = 'DEMO_TABLE';
SEGMENT_NAME | PARTITION_NAME | SEGMENT_TYPE
DEMO_TABLE | SYS_SUBP50061 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50062 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50063 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50064 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50065 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50066 | TABLE SUBPARTITION
DEMO_TABLE | SYS_SUBP50067 | TABLE SUBPARTITION

Answer 1

11.2.0.3.0
Using the following insert statements...
insert into demo_table values (1,'abc','def',null);
insert into demo_table values (2,'abc','ghi',null);
insert into demo_table values (3,'abc','jkl',null);
insert into demo_table values (4,'abc','mno',null);
insert into demo_table values (5,'pqr','abc',null);
insert into demo_table values (6,'pqr','def',null);
insert into demo_table values (7,'pqr','ghi',null);
insert into demo_table values (8,'pqr','mno',null);
insert into demo_table values (9,'stu','abc',null);
insert into demo_table values (10,'stu','def',null);
insert into demo_table values (11,'stu','ghi',null);
insert into demo_table values (12,'stu','mno',null);
insert into demo_table values (13,'vwz','abc',null);
insert into demo_table values (14,'vwz','def',null);
insert into demo_table values (15,'vwz','ghi',null);
insert into demo_table values (16,'vwz','mno',null);
I get one partition with 8 rows, one with 0 rows, and two with 4 rows. The first partition's four subparitions have 5,0,0,3 rows. The other tables only have one subpartition even after all these rows were inserted. That one subpartition has all the rows for that partition.
The query of the user_segments table still shows the same seven partitions, even though I would expect the other subparitions to materialize.
(I have the same problem - hash-hash partitions only have 1 subparititon - on a much larger table with a million-plus rows but I'm using this demo table as an example since I want to post something others can replicate)
Edit: I thought hash-hash partition support was added in 11R2?