Forum Discussion
Helper IRelationship: Star schema for multiple fact table
Dear all,
I have two fact table (Sales Table, Gift Table) and they have common look up dimension table (Customer, Product, Calender, etc).
I would like to filter out dimension based on fact, like "find customer who has bought certain amount of product A while received gift before'. This, I believe, would require a bidirectional filtering. And when I change to bidirection, Power BI would not allow it, saying there is ambigious filtering path.
My current solution would be disable/switch to "single" relationship when needed. Can you guys share your experience on design the data structure with multiple fact table? Thank you.
2 Replies
A schema can have one or more facts, but these facts are not linked by any key relationship. It is best practice not to join fact tables in a single query.Please refer these two very good articles:
Three ways to drill across by Chris Adamson
and
Should of the Warehouse - Drilling Across by Ralph Kimball
(from Stack overflow)
KeithChu,
Please check my reply in the similar thread below. If you still have questions, please share a screenshot about your relationships in the data model.
https://community.powerbi.com/t5/Desktop/Data-model-loop-cant-point-2-transaction-dates-to-DateTable/td-p/97261
Regards,
Lydia
