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https://issues.apache.org/jira/browse/KYLIN-1122?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15013018#comment-15013018
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liyang commented on KYLIN-1122:
-------------------------------
Suggest base this feature on 2.x branch. The "VALUE" measure can reuse (and
should reuse) some designs from TopN feature which is already on 2.x branch,
including:
- Storing multiple values in one measure cell
- Leverage dictionary (optional) to encode values in measure cell
- Report multiple rows out of one hbase row at query time
Shaofeng has KYLIN-943 implemented but I plan to refactor the designs a bit to
cover more generic cases like this. Will notify again when refactoring is done.
Then Xiaoyu can follow up.
Back port the feature to 1.x should be relatively easy once we have sorted out
the designs.
> Kylin support detail data query from fact table
> -----------------------------------------------
>
> Key: KYLIN-1122
> URL: https://issues.apache.org/jira/browse/KYLIN-1122
> Project: Kylin
> Issue Type: New Feature
> Components: Query Engine
> Affects Versions: v1.2
> Reporter: Xiaoyu Wang
> Assignee: liyang
> Fix For: v2.0, v1.2
>
> Attachments:
> 0001-KYLIN-1122-Kylin-support-detail-data-query-from-fact(2.x-staging).patch,
> 0001-KYLIN-1122-Kylin-support-detail-data-query-from-fact(update-v2-1.x-staging).patch
>
>
> Now Kylin does not support query correct detail rows from fact table like:
> select column1,column2,column3 from fact_table
> The jira KYLIN-1075 add the "SUM" function on the measure column if defined.
> But only the column number type is support.
> I change some code to support this issue:
> Add a "VALUE" measure function : the same value and datatype in the input and
> output of this function.
> If you want to query detail data from fact table
> *require*:
> 1.Configure the column which not dimensions to "VALUE" or "SUM" measure.(If
> not configure measure function in the column will get NULL value)
> 2.The source table must has an unique value column and configure it as
> dimension.
> If you have the better solution please comment here.
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