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https://issues.apache.org/jira/browse/KYLIN-3812?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Zhong Yanghong updated KYLIN-3812:
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Description:
Currently it's not well supported for CompareTupleFilter to have a child of
CompareTupleFilter. However, in some cases, it's better to support it.
{code}
where (colA = (1=1))
{code}
The *(1=1)* can be transformed to "true". And then this filter can be pushed
down to hbase. Otherwise, the filter *(colA = (1=1))* does not work in hbase.
And it may return incorrect results for the following SQL:
{code}
select colA
case
when colB = (1 = 1) then 'B'
when colC = (1 = 1) then 'C'
when colD = (1 = 1) then 'D'
else 'n/a'
end as phase,
count(*)
from T
where session_date between '2018-08-01' and '2018-08-31'
group by colA
case
when colB = (1 = 1) then 'B'
when colC = (1 = 1) then 'C'
when colD = (1 = 1) then 'D'
else 'n/a'
end;
{code}
In the final result, all of the keys will become 'B'.
was:
Currently it's not well supported for CompareTupleFilter to have a child of
CompareTupleFilter. However, in some cases, it's better to support it.
{code}
where (colA = (1=1))
{code}
The *(1=1)* can be transformed to "true". And then this filter can be pushed
down to hbase. Otherwise, the filter *(colA = (1=1))* does not work in hbase.
> optimize the child CompareTupleFilter in a CompareTupleFilter
> -------------------------------------------------------------
>
> Key: KYLIN-3812
> URL: https://issues.apache.org/jira/browse/KYLIN-3812
> Project: Kylin
> Issue Type: Improvement
> Components: Query Engine
> Reporter: Zhong Yanghong
> Assignee: Zhong Yanghong
> Priority: Major
> Fix For: v3.0.0
>
>
> Currently it's not well supported for CompareTupleFilter to have a child of
> CompareTupleFilter. However, in some cases, it's better to support it.
> {code}
> where (colA = (1=1))
> {code}
> The *(1=1)* can be transformed to "true". And then this filter can be pushed
> down to hbase. Otherwise, the filter *(colA = (1=1))* does not work in hbase.
> And it may return incorrect results for the following SQL:
> {code}
> select colA
> case
> when colB = (1 = 1) then 'B'
> when colC = (1 = 1) then 'C'
> when colD = (1 = 1) then 'D'
> else 'n/a'
> end as phase,
> count(*)
> from T
> where session_date between '2018-08-01' and '2018-08-31'
> group by colA
> case
> when colB = (1 = 1) then 'B'
> when colC = (1 = 1) then 'C'
> when colD = (1 = 1) then 'D'
> else 'n/a'
> end;
> {code}
> In the final result, all of the keys will become 'B'.
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