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https://issues.apache.org/jira/browse/KYLIN-1844?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15367353#comment-15367353
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liyang commented on KYLIN-1844:
-------------------------------

When creating cube, you can select "encoding" for each dimension. Dictionary is 
the default encoding. Other encodings are "int" and "fixed-length". Developer 
can also create their own encodings.

> High cardinality dimensions in memory
> -------------------------------------
>
>                 Key: KYLIN-1844
>                 URL: https://issues.apache.org/jira/browse/KYLIN-1844
>             Project: Kylin
>          Issue Type: Improvement
>          Components: Query Engine
>    Affects Versions: v1.2, v1.5.2
>            Reporter: Abhilash L L
>            Assignee: liyang
>
> A whole dimension is kept in memory.
> We should have a way to keep only certain number / size of total rows to be 
> kept in memory. A LRU cache for rows in the dimension will help keep memory 
> in check.
> Why not store all the dimensions data in hbase in a different table with a 
> prefix of dimensionid, and all calls to the dimensions (get based on dim 
> key), is mapped to hbase.
> This does mean it will cost more time on a miss.



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