Oracle的TPCC测试，原来也是个作弊的东西...

http://www.oaktable.net/content/sorted-hash-clusters-rip

根据Jonathan Lewis老先生的测试实例，发觉cluster 的sort功能，完全是为了tpcc测试而存在的，非等值的查询语句，都会走错误的计划，得出错误的结果。

这回oracle麻烦大了...

 

execute dbms_random.seed(0)



create cluster sorted_hash_cluster (

	hash_value	number(6,0),

	sort_value	varchar2(2)	sort

)

size 300

hashkeys 100

;



create table sorted_hash_table (

	hash_value	number(6,0),

	sort_value	varchar2(2),

	v1		varchar2(10),

	padding		varchar2(30)

)

cluster sorted_hash_cluster (

	hash_value, sort_value

)

;





begin

	for i in 1..5000 loop

		insert into sorted_hash_table values(

			trunc(dbms_random.value(0,99)),

			dbms_random.string('U',2),

			lpad(i,10),

			rpad('x',30,'x')

		);

		commit;

	end loop;

end;

/



begin

	dbms_stats.gather_table_stats(

		ownname		 => user,

		tabname		 =>'sorted_hash_table'

	);

end;

/



select count(*) from sorted_hash_table where hash_value = 92;

select count(*) from sorted_hash_table where hash_value = 92 and sort_value is null;

select count(*) from sorted_hash_table where hash_value = 92 and sort_value is not null;



select * from sorted_hash_table where hash_value = 92 and sort_value >= 'YR';

select * from sorted_hash_table where hash_value = 92 and sort_value > 'YR';

oracle这3000W的数值，原来是这么出来的...

 

http://www.tpc.org/tpcc/results/tpcc_perf_results.asp