Hi Abhilash,
Please refer to below comments inline.
Thanks.
Best Regards!
---------------------
Luke Han
On Thu, Dec 10, 2015 at 2:28 PM, Abhilash L L <[email protected]> wrote:
> Hello,
>
> Is there a document explaining the assumptions for incremental builds.
> *Luke: I'm afraid there's no such doc yet. what's exactly "assumption" you
> are looking for, to know the code level implementation or how to optimize?*
>
> Is it purely additive ? Lets say category id is one my row key
> components. I had 10 products on category id 20. Now I got a new product
> for same category would it add up. Would distinct count also be fine ?
>
* Luke: Kylin performs very well for such case, it will add up to 21,
also for distinct count, but the result of distinct count is approximately.*
>
> Do we allow 'updates' on a facts ?
> 1) Because of some typo the quantity came in as 100 instead of 10. What is
> the suggested approach to handle this.
>
Luke: Do you mean data model changes? Then you have to disable that
cube, purge data and refine it, the rebuild it.
2) Lets say the the value for dimension 1 was d1 in the facttable. Now it
> got updated to d2 for the same dimension. How does it 'deduct' from the
> aggregation for d1 for all cuboids and 'accumulate' for d2 in all cuboids.
>
> How to support Slowly Changing Dimensions (SCD). Support for type 2 and
> type 3.
>
* Luke: Kylin does not support SCD very well yet.*
>
> How to support deletes in fact / dimension ?
>
* Luke: delete in fact table is fine, but in dimension should be
careful, properly it will require rebuild.*
>
>
> If theres a document explaining already, it would help us and a lot of
> people.
>
>
> Regards,
> Abhilash
>
