Data Model Relationships


#1

I’ve been doing more repeats over the Advanced Data Modelling course.
Its feels like to me whenever using Power BI Data Model it should always be with 1-To-Many Rel

The Many-To-Many Rel (filtering both way) i’ve never used.
Can somenoe please explain, how and when would we need to use them? Key bullet points would really help.
Not seen anything online to show examples of why we need them.
I think if we had Many-To-Many Rel it would probably ruin a lot of the business value of using Time Intelligence anyway.

Shrik


#2

95% of the time yes one to many is the relationship to use.

I very very rarely need many to many relationships.

M2M relationships create a lot of complexities to models necessarily. And can sometimes impact performance quite a bit.

In my experience the key is to simplify simplify simplify where ever possible. It makes understanding what you are doing and what you are seeing that much easier.

Main scenario to use many to many relationship, is when one product could be in multiple categories, or one customers could live in multiple regions for example.

I think this explains it in it’s simplest form.

I plan to make a more details example of this in the near future as a tutorial.

Chrs