create table sales(trans_date date,cust_id int,sales_smount number);

insert /*+append */ into  sales
select trunc(sysdate,'year')+mod(rownum,366) trans_date,
mod(rownum,100) cust_id,
abs(dbms_random.random)/100 sales_smount from all_objects;

begin
for i in 1..4 loop
insert /*+append */ into  sales
select  trans_date,
cust_id,
abs(dbms_random.random)/100 sales_smount from sales;
commit;
end loop;
end;

create table time_hierarchy
(day primary key,mmyyyy,mon_yyyy,qtr_yyyy,yyyy)
organization index
as
select distinct trans_date day,
cast(to_char(trans_date,'mmyyyy')as number) mmyyyy,
to_char(trans_date,'mon-yyyy') mon_yyyy,
'Q'||ceil(to_char(trans_date,'mm')/3)||'FY'
||to_char(trans_date,'yyyy') QTR_YYYY,
cast(to_char(trans_date,'yyyy') as number)yyyy
from sales;
/

create materialized view mv_sales
build immediate
refresh on demand
enable query rewrite
as
select sales.cust_id,sum(sales.sales_smount),time_hierarchy.mm_yyyy
from sales,time_hierarchy
where sales.trans_date =time_hierarchy.day
group by sales.cust_id, time_hierarchy.mm_yyyy
/

select sum(sales.sales_smount),time_hierarchy.mmyyyy
from sales,time_hierarchy
where sales.trans_date =time_hierarchy.day
group by  time_hierarchy.mmyyyy

select sum(sales.sales_smount),time_hierarchy.qtr_yyyy
from sales,time_hierarchy
where sales.trans_date =time_hierarchy.day
group by  time_hierarchy.qtr_yyyy

create dimension time_hierarchy_dim
level day is  time_hierarchy.day
level mmyyyy  is time_hierarchy.mmyyyy
level qtr_yyyy  is time_hierarchy.qtr_yyyy
level yyyy      is time_hierarchy.yyyy
hierarchy time_rollup
(
day child of
mmyyyy child of
qtr_yyyy child of
yyyy
)
attribute mmyyyy
determines mon_yyyy;

篇外话：
           做测试导入的时候，对应表空间不存在，原本想通过收回创建无限空间的权限，
达到可以导入到用户对应表空间，结果不行，只好重新创建对应表空间导入。后来忘了赋予对应用户权限，结果今天创建物化视图报ora-01536  超过空间限量,初以为是表空间不够，实际是对应的用户没有无限使用表空间的权限alter user username quota unlimited on tablespacename。赋予权限后可创建，一切正常。