Forum Discussion
Cardinality error,,, or snowflake schema needed?
Hi,
I got stuck in making Snowflake Schema.
Can anybody help me, how to develop for Cardinality with correct order please?
Its part of my invoice.
I was going to calculate only sales by Service Group.
Product Dimension
Product Code Product Group Product Service Service Group
| A | Air | COACH | ECONOMY (Air) |
| A | Air | BUSINESS | BUSINESS (Air) |
| A | Air | PREMIUM ECONOMY | PREMIUM ECONOMY (Air) |
| R | Rail | BUSINESS | BUSINESS (Rail) |
| R | Rail | COACH | ECONOMY (Rail) |
| R | Rail | Rail | ECONOMY (Rail) |
Fact Dimension
| Product Code | Product Group | Product Service |
| A | Air | COACH
|
| R | Rail | BUSINESS |
In Product Dimenstion, I newly inserted the column Service Group, which doesnt exist in FACT Dimension.
The problem, is that I can not make one to many cardinality. so, i guess, i need Snowflake schema.
But, I do not have another column and data in terms of the product above in Fact dimension (invoice).
1 Reply
Your fact table is at a different grain to your dimension table.
If you can't change the grain of the fact table I would use a many to many relationship set so the dimension table filters the fact table.
