1、创建索引，从Distinct那条语句可以看出，week 选择率最好（过滤的最多）

create index T_HAHA_test on storebasepricesum(week,year,clevel) parallel 8;
alter index T_HAHA_test parallel 1;

再次执行语句

select count(*) from (
select /*+ index(tt T_HAHA_TEST) */ 
.
.
.
.
  from V_HAHA tt
	 where tt.year = 2013
	   AND (tt.week in(38) OR 38 is null)
	   AND (tt.storeid = null OR null is null)
	   AND (tt.standardid = null OR null is null)
	   AND (tt.code in (null) OR null is null)
	   AND (tt.division_no = null OR null is null)
	   AND (tt.section_no = null OR null is null)
	   AND (tt.grp_no = null OR null is null)
	   AND (tt.subgrp_no = null OR null is null)
	   AND (tt.subgrp2_no = null OR null is null)
	   AND (tt.clevel = 'store' OR 'store'  is null)
);

  COUNT(*)
----------
       334

0.01秒出结果，之前是5分多，速度提升了多少呢，来我算一算 哈哈哈哈哈哈~

优化虽易，乙方不易 ，且行且特么珍惜。