Here’s a recording of a session I did for the Manchester (UK) Power BI user group recently on best practices for DirectQuery mode in Power BI:
I’ve done it for a few other groups over the last six months but this is the latest and best version, I think.
I’ve worked with several customers using DirectQuery mode since I joined the CAT team and learned a lot along the way. Some of this knowledge has been written up by me (eg this post on Snowflake DirectQuery mode best practices), some of it by the people who work with the data sources Power BI runs on top of (see posts by Dany Hoter on the Azure Data Explorer blog, for example; there’s also going to be a lot of new material on DirectQuery for Databricks coming soon, with this post as a start). There’s a lot of detailed information in the docs too, for example here, here and here.
But remember folks: the most important piece of advice around DirectQuery is to not use it unless you’re really, really, really sure you have no other option. It’s possible to make it work well but it takes a lot more tuning and specialist skill than Import mode!