Performance: Real time dashboard vs. Power BI report DirectQuery to KQL

[frithjof_v]

Hi,

In theory (and practice), is there a performance difference between a Real Time Dashboard and a Power BI report with DirectQuery to the same KQL source?

If yes, what are some main drivers for this performance difference?

[datacoffee]

A bit yes. This is one of the things that might slow down the performance in Power BI

Please remember to mark an answer as accepted so other people can find the correct answer to this question 😊

[datacoffee · Accepted solution]

Someone might kill me for writing this. 

the Power bi engine is not as fast as the Kusto engine to handle data.

with this said, then power bi tries to fold all queries to the Kusto engine for it to do all the work. Query folding from power bi is happening more often towards the KQL engine than the sql engine. 

so in theory the rtd would be more effective and performant  when working with Kusto data than power bi. But I don't think you u will be able to measure a real experienced difference 

cheers

[frithjof_v]

Thanks!

Yes, I am assuming that the required DAX -> KQL conversion will make the Power BI report a bit slower than the native KQL Real Time Dashboard.