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From ShaoFeng Shi <shaofeng...@apache.org>
Subject Re: Dimension update issue
Date Tue, 03 Apr 2018 02:22:02 GMT
Hi Roberto,

Kylin will take the snapshot for dimension tables, and persist the
snapshots together with the cube segments.

If you have modified the dimension table in Hive, and expects to see the
changes for history segments, the proper way is to refresh the history
segment(s), which will refresh the snapshot.

Hope this clarifies your questions.



2018-04-03 0:00 GMT+08:00 <roberto.tardio@stratebi.com>:

> Hi,
>
>
>
> I have some questions about how Kylin refresh dimensions tables.  In case
> you delete some instances of the dimension on hive table that are not used
> by any fact in fact table, These values will be deleted from dimension
> table on next cube segment built? We have to refresh old segments?
>
>
>
> In our case we have added by mistake a lot of empty future days to a Date
> dimension (80 years). Then we have built some days of the cube. However, as
> this big date dimensions leads to performance issues, we have deleted most
> of future years from Date dimension. However, after built a new segment of
> the cube, the deleted rows on Hive table they have not been deleted in
> Kylin cube table. How can we refresh the dimension table on Kylin properly?
>
>
>
> Thanks in advance!
>
>
>
> *Roberto Tardío Olmos*
>
> *Senior Big Data & Business Intelligence Consultant*
>
> Avenida de Brasil, 17
> <https://maps.google.com/?q=Avenida+de+Brasil,+17&entry=gmail&source=g>,
> Planta 16.28020 Madrid
>
> Fijo: 91.788.34.10
>
>
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> http://www.stratebi.com/image/layout_set_logo?img_id=21615&t=1486381163544]
>
>
>
> http://bigdata.stratebi.com/
>
>
>
> http://www.stratebi.com
>
>
>



-- 
Best regards,

Shaofeng Shi 史少锋

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