[
https://issues.apache.org/jira/browse/KYLIN-1313?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15097779#comment-15097779
]
Yerui Sun commented on KYLIN-1313:
----------------------------------
Thanks for your clearly explanation with many details.
I agreed with the trade off between functionality and performance, only item_id
could be filtered is acceptable. If there's indeed requirements for item_url
filtering, it can be added as a individually dimension, right?
But I still has questions on this:
* With the 'heavy deriving' supporting, the current 'light weight deriving'
will be still reserved or not? There seems no conflicting between these two
deriving features;
* Is it possible to support one-to-many deriving? In your example, suppose
there's one more column called item_description, is it possible to fetch both
item_url and item_description by item_id filtering?
* Why don't we backport this feature to 1.x-staging branch? We really need this
feature in 1.x-staging production environments, and I'm not is there any
unsolvable problems for backporting?
Thanks for your working on this, and please let me know if there's any I could
help.
> Enable deriving dimensions on non PK/FK
> ---------------------------------------
>
> Key: KYLIN-1313
> URL: https://issues.apache.org/jira/browse/KYLIN-1313
> Project: Kylin
> Issue Type: Improvement
> Reporter: hongbin ma
> Assignee: hongbin ma
>
> currently derived column has to be columns on look table, and the derived
> host column has to be PK/FK(It's also a problem when the lookup table grows
> every large). Sometimes columns on the fact exhibit deriving relationship
> too. Here's an example fact table:
> (dt date, seller_id bigint, seller_name varchar(100) , item_id bigint,
> item_url varchar(1000), count decimal, price decimal)
> seller_name is uniquely determined by each seller id, and item_url is
> uniquely determined by each item_id. The users does not expect to do
> filtering on columns like seller name or item_url, they just want to retrieve
> it when they do grouping/filtering on other dimensions like selller id, item
> id or even other dimensions like dt.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
