How does Import Query Mode refreshing work?

[JackFrench]

I adopted a new dashboard that has numerous queries using both import and direct query modes. To my understanding, Direct Query Mode creates a live connection to the database that retrieves data in almost real-time. I also believe that in Direct Query Mode, all visuals on your screen will rerun a query to the database to generate your desired value(s), leading to slower performance. 

When it comes to Import Mode, I understand that the data is imported into the semantic model and updated upon request. Since the data is already stored in PBI it allows for faster changes, adjustments, and loading, correct? My question to you all is: how are the tables using Import mode currently up to date (I verified by checking the date), even though it says in the image I have attached that the last refresh was back in December? The image attached is a screenshot of the data model in the model view for one of the import queries. It says the last refresh was on December 5th, 2024. However, every time I log onto the published version of this dashboard in a browser, the data in the actual table is up to date with the current date displayed.

I just want to understand if a manual or automatic refresh schedule is even needed. It appears that it is being refreshed upon opening the dashboard in a browser? If this is the case, why does the refresh date on the desktop application say it's a month overdue? I'd like to convert the direct query mode tables to import mode if refreshing upon opening is an option.

[Uzi2019]

Hi @JackFrench 

Your report on service must be auto refresh on daily basis. Even though your desktop version is showing Dec update.

Automatic schedule is needed when pulling data daily basis in your report(PBI service). and manually refresh is needed when you are making changes in PBI dektop.

You cant setup a daily auto refresh to your desktop report. you have to manually refresh it by clicking on refresh button.

but Once your report is published you , once your setup a auto refresh on PBI service , It automatically fetches data on daily basis without human intervention. that's why you see latest date on PBI service report not on Desktop version.

PBI service report and PBI desktop report are independent refresh. 

I hope I answered your question!

[ToddChitt]

Your assumpitons about the differences between Direct Query and Import modes are correct. 

As far as the Last refresh displayed:

You can build a Power BI model with Import data, save it, and publish it to Power BI service, then set up a refresh schedule for that data. At that point, the data in the saved model is now going stale while the data in the Power BI Service is getting refreshed.

Can you show us a screenshot of the Last Refresh from the Power BI Service?

[AmiraBedh · Accepted solution]

I think the behavior you're observing with up-to-date data in Import mode tables, despite the "last refresh" in Power BI Desktop showing an older date, is likely due to a scheduled refresh in the Power BI Service.

While Import mode datasets require manual or scheduled refreshes to stay current, the refresh schedule configured in the Power BI Service make sure that the data remains up-to-date in the published report, even if it appears outdated in Power BI Desktop.

This discrepancy may happenbecause the "last refresh" in Desktop reflects only local refreshes, not those performed on the service.

Direct Query tables, in the other hand, fetch real-time data directly from the source every time the report is loaded.  Another thing, if a refresh schedule exists, the data is likely being updated automatically.

Check this link it can help you Power BI official documentation on scheduled refresh and hybrid datasets to better understand these behaviors and configure your dataset in a better way. If all tables are necessaryfor Import mode, you can improve performance by switching from Direct Query and make surescheduled refreshes are in place.

[JackFrench]

My  query returns 400+ million rows. I currently have his connection loaded in using Direct Query mode. Would Import Mode be best for handling large data sets like this? If import mode is able to refresh on schedule and can handle 400 million rows better than direct query then I would rather switch the connection type too.