How Direct Query Report works

[cuongle]

I have direct query report on Power BI service and setup the gateway for it, it works perfectly but one thing I am a little confused is the refresh history table for direct query report (Settings-> Datasets)  as below:

It refreshs around every 20 minutes. I thought in direct query mode, when you change the data on database it will affect the report immediately. But based on that, even in the direct query mode, it has internal cache doing refresh 20 minutes (don't know this number can be controlled).

Please can someone explain in detail how direct query works and why this?

[wonga]

@cuongle

I was under the impression that DirectQuery reports don't have scheduled refresh or any kind of refresh at all. What is your underlying data source? The only example I can work off of on my end is Oracle where I don't see anything when going into settings for the dataset.

The DirectQuery report should operate as you mentioned, where any interaction with the report should send a query back to your on premises data source to get the latest information and render the results on the report in the Power BI service. Of course you will need to have set up the on premises data gateway in order for this to work.

[cuongle]

@wonga I did setup on-premises data gateway for SQL Server, it's odd that you cannot see it with Oracle.

[ankitpatira]

@cuongle I've noticed that too. As per my understanding with directquery no data is imported in power bi and everytime you interact with visual queries are sent back to data source and data is returned with very less interal caching. I haven't been able to find detailed doc on inner workings of directquery and never really bothered to look into that much detail. You can perhaps contact microsoft and try get more info on that.