环境:

30.119上安装了oracle 11g最稳定版本11.2.0.4，已经导入10g tpch数据
登录oracle数据库
su - oracle
sqlplus test/oracle    // tpch数据都创建在test用户下，已赋予dba权限

10g数据，在oracle中慢sql17执行需要7秒

SQL> select
  2     sum(l_extendedprice) / 7.0 as avg_yearly
  3  from
  4     lineitem,
  5     part
  6  where
  7     p_partkey = l_partkey
  8     and p_brand = 'Brand#23'
  9     and p_container = 'MED BOX'
 10     and l_quantity < (
 11             select
 12                     0.2 * avg(l_quantity)
 13             from
 14                     lineitem
 15             where
 16                     l_partkey = p_partkey
 17     );

AVG_YEARLY
----------
3295493.51

Elapsed: 00:00:07.51

以慢sql17为例，查询sql执行计划

explain plan for select
	sum(l_extendedprice) / 7.0 as avg_yearly
from
	lineitem,
	part
where
	p_partkey = l_partkey
	and p_brand = 'Brand#23'
	and p_container = 'MED BOX'
	and l_quantity < (
		select
			0.2 * avg(l_quantity)
		from
			lineitem
		where
			l_partkey = p_partkey
	);
	
SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 3341365018

------------------------------------------------------------------------------------------
| Id  | Operation             | Name     | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT      |          |     1 |    13 |       |   309K  (1)| 01:01:56 |
|   1 |  SORT AGGREGATE       |          |     1 |    13 |       |            |          |
|   2 |   VIEW                | VW_WIF_1 | 60082 |   762K|       |   309K  (1)| 01:01:56 |
|   3 |    WINDOW SORT        |          | 60082 |  2522K|  3328K|   309K  (1)| 01:01:56 |
|*  4 |     HASH JOIN         |          | 60082 |  2522K|       |   308K  (1)| 01:01:48 |
|*  5 |      TABLE ACCESS FULL| PART     |  2000 | 56000 |       | 10473   (1)| 00:02:06 |
|   6 |      TABLE ACCESS FULL| LINEITEM |    59M|   858M|       |   298K  (1)| 00:59:40 |
------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   4 - access("P_PARTKEY"="L_PARTKEY")
   5 - filter("P_CONTAINER"='MED BOX' AND "P_BRAND"='Brand#23')