Forum Discussion
Need Help with Data Model
Hi TimmK ,
the best practices refer to Power BI as a model based tool and not as a report based tool. The goal here is to design a data model that can be applied to various questions and reports.
With a good data model you have common dimensions by which you can view your different metrics. At the same time, your model should be stable in case of changes, e.g. if you need to add another dimension or metric.
For example, the date dimension is one of the most important dimensions from my point of view and should be linked to almost every fact table. So, if modeled correctly, you can determine the inventory at any point in time (running total), your consumptions or receipts at certain points in time, and the delivery quantity at the delivery date.
A good BI data model should give analysis capabilities and not just solve a reporting question.
Hi TimmK ,
To build a reasonable star model, you first need to understand its design principles: Dimension tables support filtering and grouping, Fact tables support summarization. There are cardinal attributes and screening directions, both of which also play a key role in the construction of the model. Based on the above and refer to the official documents, I hope to help you.
Here is the reference link:
Understand star schema and the importance for Power BI - Power BI | Microsoft Docs
If the problem is still not resolved, please provide detailed error information and let me know immediately. Looking forward to your reply.
Best Regards,
Henry
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Hi Henryk,
Thank you, I already know the reference, but this does not really help in my practical example.
For example, is a table that is originally a fact table still a fact table after I have aggregated it with the query editor with a group by function? Because then it only has rows with a unique PK and in this case it would be a 1:1 relationship to the item table. Thus, I wonder if I should just merge it with the item table?