The Power Query OData.Feed function has an option called IncludeAnnotations that allows you to return annotation values from an OData data source. It’s not obvious how to use it though – even if you use this option when connecting, you won’t see the annotation values by default because they are returned as metadata.
With the release of the July 2020 version of Power BI desktop we can create tools that can interreact with the Power BI Desktop model directly using an external tool. With this interaction you can make changes to the model in a programmatic way. There are so opportunities things this will open up. You can think of a tool that would allow you to edit the model like Tabular Editor or query like DAX Studio (which both already work as external tools).
When you merge data from two queries in the Power Query Editor the M code generated uses the Table.NestedJoin function. There is, however, another M function that can be used to merge data: Table.Join. The interesting thing about this function is that has a parameter that Table.NestedJoin doesn’t have: the joinAlgorithm parameter allows you to specify the algorithm used by the Power Query engine for the merge.
If you’re working with large amounts of data in Power BI you may find that you have problems because:
In the April release of Power BI Desktop the Power Query Query Diagnostics feature was enhanced so that you can now return performance counter data. As the blog post says:
When you run performance counters, every half second Power Query will take a snapshot of resource utilization. This isn’t useful for very fast queries but can be helpful for queries that use up a lot more resources.