for case 1:

do you mean that you want to derive region_name from region_id, city_name
from city_id?

for case 2:

theoretically it can be hacked by modifying metadata store only, however,
it can be very complex and error prone

On Wed, Jun 17, 2015 at 2:50 PM, dong wang <[email protected]> wrote:

> usually, we may have 2 common cases:
> 1, only have a fact table which has already been joined with lookup tables,
> take it as a wide table
>
> 2, we have star schema data model, and when defining the cube, we define
> the join with the fact table and lookup tables,
>
> currently,
>
> to the 1st case, we cannot create derived dimensions based on the fact
> table which can be created only from the lookup tables,  for example, we
> have fact table: region_id, region_name, province_id, province_name,
> city_id, city_name, M1, M2, ...Mn, we want to create a hierarchy dimension:
> region_id->province_id->city_id, and a derived dimenison: (region_name,
> province_name, city_name) as well, if we can achieve it, there will be no
> complicated joins at all, and also, the join will take much time in the
> first step when building the cube~ thus, will we support such demension
> design?
>
> to the 2nd case, even though we make the join, however, if the column names
> are changed for some reasons, we will have to build the whole cube again
> instead of only update the dimension data?
>



-- 
Regards,

*Bin Mahone | 马洪宾*
Apache Kylin: http://kylin.io
Github: https://github.com/binmahone

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