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https://issues.apache.org/jira/browse/HIVE-13602?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15255914#comment-15255914
]
Nemon Lou commented on HIVE-13602:
----------------------------------
Another information : after rewrite q16 into the following form,CBO can return
right result:
{noformat}
select
p_brand,
p_type,
p_size,
count(distinct ps_suppkey) as supplier_cnt
from
partsupp
left outer join (
select
s_suppkey
from
supplier
where s_comment like '%Customer%Complaints%'
) sq_1 on partsupp.ps_suppkey = sq_1.s_suppkey
join
( select count(*) as cn from (select * from supplier where s_comment like
'%Customer%Complaints%' ) b where s_suppkey is null) a
on a.cn= 0
join part
where
p_partkey = ps_partkey
and p_brand <> 'Brand#34'
and p_type not like 'ECONOMY BRUSHED%'
and p_size in (22, 14, 27, 49, 21, 33, 35, 28)
and 1 = 1 and sq_1.s_suppkey is null
group by
p_brand,
p_type,
p_size
order by
supplier_cnt desc,
p_brand,
p_type,
p_size;
{noformat}
> TPCH q16 return wrong result when CBO is on
> -------------------------------------------
>
> Key: HIVE-13602
> URL: https://issues.apache.org/jira/browse/HIVE-13602
> Project: Hive
> Issue Type: Bug
> Components: CBO, Logical Optimizer
> Affects Versions: 1.2.1
> Reporter: Nemon Lou
> Assignee: Pengcheng Xiong
> Attachments: explain_cbo_bad_part1.out, explain_cbo_bad_part2.out,
> explain_cbo_bad_part3.out
>
>
> Running tpch with factor 2,
> q16 returns 1,160 rows when CBO is on,
> while returns 59,616 rows when CBO is off.
> See attachment for detail .
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