Forum Discussion
Best practices for working with star model?
Community ChampionAnonymous If you've such large number of tables to work with each having PK FK relations then DirectQuery is the best option. When Powerbi desktop import tables it doesn't look at your PK, FK relations but tries to determine relations on its own based on few rules such as it uses field names to determine relations. For example P_ID in one table will be linked with P_ID in other table. So then it would try and determine as many relations it can and leave other blank or inactive (inactive due cardinality conflicts).
If you absolutely needs to use Import then I would suggest create relations between each tables manually via relationship editor.
As you can see in the last picture I let disable the automatic creation of relationships between the tables at the time of loading, the dimensions of the relationship to the fact table were done manually after loading the data
- ankitpatira
Anonymous also ensure cross filter direction is set to Single for all the relations and then you will be able to also add relations for the tables that is missing currently. If you have cross filter direction to Both unfortunately you won't be able to set relations for all the tables.
- ImkeF
If you're moving from a working Qlickview to PowerBI I see no reason at all to modify table structures. It's a reporting-system (read only), serving the same purpose just like Power BI and if it has been designed according to good practices and performs alright - no reason to adjust the model.
From my personal experience I can say that if peoply don't really understand data modelling (including basic understanding of the business processes involved), there is a very high chance that they only make things worse they start to modify it.
My recommendation: Build a proper foundation of data modelling understanding before you get going on this terrain. I wouldn't argue against jumping head-first into many IT areas, but this is one of the few where I strongly recommend against!
