问题
We are implementing Power BI with SSAS Cube Direct Query. For some reason, SSAS Power BI is extremely slow performance, however using SSDT SSAS Application or Power View or Excel is Much faster.
I read that Power BI converts SSAS Multidimensional models by converting MDX to a DAX query. Is there any method to speed up Power BI queries for SSAS, or use MDX queries directly?
We are applying SSAS Multidimensional model.
回答1:
I don't think that the performance issue is caused by converting MDX into DAX since Direct Query doesn't convert the query. On the other hand Direct Query has many limitations and it is not always recommended.
Two years ago, the Power BI team created a topic for improving Direct Query
I don't think there is a direct solution for a generic case (using SSAS Multidimensional with Power BI), but you must read more about the Direct Query limitations, best practices and use cases.
Referring to the following official documentation, there are some best practices for using Direct Query:
- DirectQuery best practices
References and Helpful articles
- Direct Query with Power BI
- Using and optimizing DirectQuery in #powerbi and #ssas #tabular
- Using DirectQuery in Power BI
- Introduction to DirectQuery
回答2:
PowerBI is slower than Tableau for sure due to its nature Try to compare the performance between PowerBI connecting to SQL server vs PowerBI connecting to SSAS, if the performance is similar then then should call Microsoft people for help. If performance is much faster when connecting to SQL then try to write MDX directly to see if performance improved.
来源：https://stackoverflow.com/questions/55484707/power-bi-slow-with-ssas-multidimensional-cube