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db2的优化器还是很认sql的
前面那个
---------------------------------------------
* Comment: " Q20"
---------------------------------------------
* SQL Statement Number 20:
select
s_name,
s_address
from
tpch.supplier,
tpch.nation
where
s_suppkey in (
select
ps_suppkey
from
tpch.partsupp
where
ps_partkey in (
select
p_partkey
from
tpch.part
where
p_name like 'bisque%'
)
and ps_availqty > (
select
0.5 * sum(l_quantity)
from
tpch.lineitem
where
l_partkey = ps_partkey
and l_suppkey = ps_suppkey
and l_shipdate >= date '1994-01-01'
and l_shipdate < date '1994-01-01' + 1 year
)
)
and s_nationkey = n_nationkey
and n_name = 'CANADA'
order by
s_name
fetch first 10 rows only;
S_NAME S_ADDRESS
------------------------- ----------------------------------------
Supplier#000000020 iybAE,RmTymrZVYaFZva2SH,j
Supplier#000000091 YV45D7TkfdQanOOZ7q9QxkyGUapU1oOWU6q3
Supplier#000000205 rF uV8d0JNEk
Supplier#000000285 Br7e1nnt1yxrw6ImgpJ7YdhFDjuBf
Supplier#000000287 7a9SP7qW5Yku5PvSg
Supplier#000000354 w8fOo5W,aS
Supplier#000000361 f8IUYRmdVXhQC9qJQjWknCXmzhe38vCbk6
Supplier#000000475 xw4V6,4QQW LI5Qg EOKy4JD B4Cq1tjzaOma9Y
Supplier#000000530 0qwCMwobKY OcmLyfRXlagA8ukENJv,
Supplier#000000532 ep92hT7VLaVlDKM7lgbj02kIL
* 10 row(s) fetched, 10 row(s) output.
* Elapsed Time is: 587.439039 seconds
改了后
-sh-3.2$ date; time db2 -tvf /user1/ibm/q20newkid.sql ;date
2011年 05月 12日 星期四 19:19:05 CST
select s_name, s_address from supplier, nation where s_suppkey in (select ps_suppkey from partsupp ,(select l_partkey,l_suppkey, sum(l_quantity) l_quantity_SUM from lineitem,part where l_partkey = p_partkey and p_name like 'bisque%' and l_shipdate >= date '1994-01-01' and l_shipdate < date '1994-01-01' + 1 year GROUP BY l_partkey,l_suppkey ) where l_partkey = ps_partkey and l_suppkey = ps_suppkey and ps_availqty > 0.5*l_quantity_SUM ) and s_nationkey = n_nationkey and n_name = 'CANADA' order by s_name fetch first 10 rows only
S_NAME S_ADDRESS
------------------------- ----------------------------------------
Supplier#000000020 iybAE,RmTymrZVYaFZva2SH,j
Supplier#000000091 YV45D7TkfdQanOOZ7q9QxkyGUapU1oOWU6q3
Supplier#000000205 rF uV8d0JNEk
Supplier#000000285 Br7e1nnt1yxrw6ImgpJ7YdhFDjuBf
Supplier#000000287 7a9SP7qW5Yku5PvSg
Supplier#000000354 w8fOo5W,aS
Supplier#000000361 f8IUYRmdVXhQC9qJQjWknCXmzhe38vCbk6
Supplier#000000475 xw4V6,4QQW LI5Qg EOKy4JD B4Cq1tjzaOma9Y
Supplier#000000530 0qwCMwobKY OcmLyfRXlagA8ukENJv,
Supplier#000000532 ep92hT7VLaVlDKM7lgbj02kIL
10 record(s) selected.
real 0m25.700s
user 0m0.013s
sys 0m0.011s
2011年 05月 12日 星期四 19:19:31 CST |
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