If a Power BI report does not open due to many-to-many relationships, such relationships may be the case that such relationships add to performance issues or circular dependencies. Here is how you can resolve this issue and get access again to the report:
1. Bridge Table
A bridge table is a typically used solution for many-to-many relationship problems. It serves as the bridge between the tables stuck in many-to-many.
Steps:
Make a new table of unique keys from both sides of the many-to-many relationship. Create one-to-many relationships for this bridge table with the two tables at either end. This structure avoids many-to-many relationships and improves performance.
2. DAX measures instead of relationships
If possible, you can build a DAX measure that calculates the metrics needed to avoid building complex relationships over many-to-many ones.
Solution: Create a DAX measure that calculates the rationale of the relationship rather than the relationships existing in the model.
3. Temporarily Remove or Disable the Relationships
If the report will not open, turn off the relationships temporarily and then edit them.
Steps:
Open the report in Power BI Desktop (Model view).
Deactivate the offending relationships, right-click, and choose this for all. Save the file and try to open that report again.
Once opened, try to modify the report's relations or replace them with simpler ones, such as one-to-many.
4. Simplify the Data Model
Sometimes, the direct result of way too many interrelated tables could take the form of a complex relationship. To resolve the above, the following actions need to be undertaken:
Fix: Scrutinize and purge unnecessary relationships in the data model, thus simplifying the model by redundant relationships or merging tables where they still apply.
5. Look For Circular Dependency
When tables were indirectly linked, a circular dependency was established, causing the reports to fail to open.
Fix: Eliminating or reconfiguring relevant relationships will identify them. This is done in the Model view by checking for red warnings showing circular dependencies.
6. Optimize the Data Model.
If the report refuses to open with the large datasets and complex relationships as the cause of the loading delay, Fix: Filter unnecessary rows, create aggregates, or make improvements in DAX calculations for performance purposes.
Here is how you can ultimately liberate yourself from the many-to-many relationship by bridge tables, DAX measures, or simplification of relationships so that you can get back access to the report and edit it more comfortably.
