Star schema [fact 1:n dimension]...how?

Question

I am a newcomer to data warehouses and have what I hope is an easy question about building a star schema:

If I have a fact table where a fact record naturally has a one-to-many relationship with a single dimension, how can a star schema be modeled to support this? For example:

Fact Table: Point of Sale entry (the measurement is DollarAmount)
Dimension Table: Promotions (these are sales promotions in effect when a sale was made)

The situation is that I want a single Point Of Sale entry to be associated with multiple different Promotions. These Promotions cannot be their own dimensions as there are many many many promotions.

How do I do this?

I'm in two minds whether this belongs here or on stackoverflow. Star Joins are not something I've had to deal with before... — Mark Henderson, May 06 '10 at 23:21
Possible duplicate of [Star schema \[fact 1:n dimension\]...how?](http://stackoverflow.com/questions/2785158/star-schema-fact-1n-dimension-how) — Jo Douglass, Dec 13 '16 at 16:48

score 1 · Answer 1 · answered Feb 07 '11 at 23:03

1

Use bridge table

fact table=>promotion group dimension=>promotion group bridge table=>promotion

Read Kimball books' they help a lot ;-)

answered Feb 07 '11 at 23:03

ETL Man

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Can you confirm that in this scenario, it can not be determined "how much of the sale" is attributed to each individual promotion, so there is no drilling down from promotion group to one particular promotion or another - is that correct? – qxotk Feb 06 '14 at 21:47

Star schema [fact 1:n dimension]...how?

1 Answers1

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