[
https://issues.apache.org/jira/browse/KYLIN-3402?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16509697#comment-16509697
]
Shaofeng SHI commented on KYLIN-3402:
-------------------------------------
hi lemont, now count(distinct 'expression') is not supported yet.
You can try to define a hive view, in which adding a column for the
'expression', and then define a COUNT DISTINCT measure for the new column. Then
the pre-calculated measure can be used to accelerate the query.
> kylin not support count distinct in sub
> ---------------------------------------
>
> Key: KYLIN-3402
> URL: https://issues.apache.org/jira/browse/KYLIN-3402
> Project: Kylin
> Issue Type: Improvement
> Reporter: Lemont
> Priority: Major
>
> why kylin not support count distinct in innermost sub-query.To deal with it
> I have to try another way to write sql,it's very complicated.
> For example id is the Dimensions：
> select count( DISTINCT case when condition = 1 then id end) idCount
> from (
> select condition,id
> from table
> where xxx
> group by xxx
> )
> To support count distinct I hava to rewrite it to:
> select count(1) from (
> select case when condition = 1 then id end idCount
> from (
> select condition,id
> from table
> where xxx
> group by xxx
> ) group by idCount
> )
> I feel so bad with it ,Is there a better solution?
> Thanks to every answer
>
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
