create table tbl
(
   dt      date not null
  ,type    number not null
  ,value   number not null
)
partition by range (dt)
   interval ( interval '1' day )
   subpartition by hash (type) subpartitions 1024
   (partition values less than (date '2017-01-01'));

Table created.


insert into tbl values (trunc(sysdate),1,1);

1 row created.

select sum(blocks)*8/1024 size_mb from user_segments where segment_name = 'TBL';

   SIZE_MB
----------
      8192


drop table tbl;

Table dropped.


create table tbl
(
   dt      date not null
  ,type    number not null
  ,value   number not null
)
partition by range (dt)
   interval ( interval '1' day )
   subpartition by hash (type) subpartitions 1024
   (partition values less than (date '2017-01-01'))
storage (initial 64k next 64k);

Table created.


insert into tbl values (trunc(sysdate),1,1);

1 row created.

select sum(blocks)*8/1024 size_mb from user_segments where segment_name = 'TBL';

   SIZE_MB
----------
        64